These AP 7th Class Science Important Questions 6th Lesson Electricity will help students prepare well for the exams.
AP Board 7th Class Science 6th Lesson Important Questions and Answers Electricity
Question 1.
How does a bulb glow?
Answer:
When we switched ON the bulb, electricity flows through the wire and makes the bulb glow.
Question 2.
What is a cell?
Answer:
A cell is a device used to generate electricity.
Question 3.
What are the anpde and cathode in a cell?
Answer:
- Anode and cathode are the two electrodes in a cell.
- The positive electrode is called anode and the negative electrode is called cathode.
Question 4.
What is the electrolyte in a cell?
Answer:
The electrolyte is a chemical component that conducts the electricity.
Question 5.
Which parts of the battery function as an anode and a cathode?
Answer:
- The container which is made of zinc metal works as the cathode (negative terminal).
- A carbon rod with a metal cap works as an anode (positive terminal).
Question 6.
Name the common chemicals present in the dry cell.
Answer:
- Carbon powder
- Ammonium chloride.
Question 7.
What Is a battery?
Answer:
A group of cells Is called a battery.
Question 8.
Write different types of cells.
Answer:
1) Dry cell, 2) Lithium cell, 3) Button ceils, 4)Alkaline cell
Question 9.
Write one difference between fuse and MCB.
Answer:
There is no need to change the fuse wire in MCB. But fuse wire has to be changed whenever it melts in fuse device.
Question 10.
What precantion do you take while connecting copper wire in the circuit?
Answer:
While connecting copper wire in the circuit, the copper coating at the two ends erf the copper wire should be cleaned or scratched.
Question 11.
What is a simple electric circuit?
Answer:
A simple electric circuit consisting of a battery, a bulb, a switch, and connecting wires.
Question 12.
What are circuit diagrams?
Answer:
The diagrams which show the arrangement of electric components in a circuit are called circuit diagrams.
Question 13.
Write the common sequence of components in electric circuit diagram.
Answer:
Positive terminal of the cell → wire → bulb → wire → switch → wire → negative terminal of the cell.
Question 14.
What is the tearing effect of electricity?
Answer:
The production of heat due to the flow of electricity through a wire is called heating effect of electricity.
Question 15.
Name the metal used as a filament in the iron box and buld?
Answer:
- Generally, the filament in an iron box is made up of Niehrome.
- The filament in a bulb is made of Tungsten.
Question 16.
What is magnetic effect of electricity?
Answer:
The production of magnetic force due to the flow of electricity thrombi a wire is called Magnetic effect of electricity.
Question 17.
What are electromagnets?
Answer:
The devices which act as magnets when electricity passes through them are called electromagnets.
Question18.
On what principle do electric cranes work?
Answer:
Electric cranes are worked on the principle of magnetic effects of electricity.
Question 19.
Answer:
- By using repulsion property of a magpet, a magnetic object can levitate.
- Electromagnetic train runs on this principle.
Question 20.
How does electricity bill calculated?
Answer:
Generally, electricity bills are calculated on the basis of number of units of electricity consumed.
Question 21.
What is wattage of a bulb? What does it mean?
Answer:
- 1) The wattage measures how powerful the electric device is.
- The brighter the bulb, the higher its wattage and more the electricity used by it.
Question 22.
What is meant by KWH?
Answer:
- Wiser? I kilo watt is used per one hour, it Is considered as 1 kilo watt hour (KWH)
- 1 KWH = 1 UNIT of electricity.
Question 23.
What is the unit of electricity consumption?
Answer:
Kilo watt hour (or) UNIT.
Question 24.
From where electricity soppiied to owr booses?
Answer:
Electricity supplied to our houses comes ban the power stations and substations.
Question 25.
Where do we use lithium-ion cells and why?
Answer:
Lithium ion cells are rechargeable and are used in mobile phones, laptops etc.
Question 26.
Where do we use button cells?
Answer:
Button cells are used in wrist watches, laser lights. thermometers (electronic), computers etc.
Question 27.
Where is the use of a switch?
Answer:
Switch is used to open or dose a circuit.
Question 28.
Write different types of Im21» which areasedht omr daily life.
Answer:
In our daily life we use different types of bulbs. Some of them are Incandescent bulb, fluorescent both (tube light). CFL (Compact Fluorescent Lamp), LED bulb etc.
Question 29.
What is the use of parallel connection of cells in a circuit?
Answer:
The parallel connection of cells, increases the battery life.
Question 30.
Guess, what happens if one of bulbs is burnt in a series connection?
Answer:
It one of the bulbs is burnt, remaining bulbs also not glow because of circuit is opened.
Question 31.
What are the material required to make a cell with lemons?
Answer:
Zinc plate, copper plate, a small bulb, or LED, connecting wires, crocodile dips, and lemons.
Question 32.
Where do you find series and parallel connections of bulbs in your real life?
Answer:
- Parallel connections of bulbs are found in houseshold connections.
- Series connections of bulbs are found in decorative purpose connections.
Question 33.
What are the risks of electric shock?
Answer:
Explosure to electricity may result in no injury at all or may result in major damage or sometimes lead to death also.
7th Class Science 6th Lesson Electricity Short Questions and Answers
Question 1.
Answer:
- A cell is device used to generate electricity.
- It contains two elect rides and a chemical.
- When electrodes come in contact with electrolyte, a chemical reaction takes place inside the cell to produce electricity.
- It converts the chemical energy into electrical energy.
- When electrodes and connected to the wires in a circuit, electricity passes through them.
Question 2.
What are the main components of a cell? Explain.
Answer:
- A cell is a device used to generate electricity.
- It mainly consists of two components.
i) Electrolyte : This is a chemical component that conducts the electricity.
ii) Electrodes : There are two electrodes in a cell. One is positive electrode called anode and the other is negative electrode called cathode.
Question 3.
Why and how do we save electricity?
Answer:
- Our country faces shortage of electricity.
- So, we should use electricity careful! and only when it is needed.
Question 4.
How long a dry cell works?
Answer:
- The cell can supply electricity in a circuit for a period of time.
- After that, chemicals present in it get exhausted and it cannot produce electricity.
Question 5.
Why should we replace an ordihary bulb with a LED bulb?
Answer:
- The ordinary bulb we use gives us light and also heat.
- This is not desirable.
- This results in the wastage of electricity.
- Hence, we should replace an ordinary bulb with a LED bulb.
- LED bulbs consume less electricity than ordinary bulb.
Question 6.
How do you find an electrical device which consumers less electricity?
Answer:
- Now-a-day every electrical device is marked with a power saving guide which contains star symbols.
- The number of stars on them indicates the energy efficiency of that device.
- The electrical appliance with more stars consumes less electricity.
- Hence, it is advised to select electrical appliances with more stars.
Question 7.
How does an electric fuse protect home appliances?
(OR)
How do you appreciate the electric fuse?
Answer:
- Electric appliances may get damaged when excess of electricity flows through them.
- To protect them from such accidents, a safety device called electric fuse is used.
- Electric fuse has a body made of ceramic.
- It has two points for connecting the fuse wire.
- If there is an overload of electricity in the circuit, the fuse wire melts because of low melting point.
- This breaks the circuit and helps in preventing damage to electrical appliances.
Question 8.
How does a MCB work?
(OR)
How do you appreciate the role of MCB in the protection of electrical home appliances?
Answer:
- MCB means Miniature Circuit Breaker.
- It is being used in place of electric fuses.
- There is a switch which automatically turns off when electricity in circuit exceeds the safe limit.
- So, the circuit is opened.
- We just need to switch ON to resume electric supply.
- At present MCB is available with automatically resumed built-in mechanism.
- MCB is better than electric fuses.
- There is no need to change it often.
- But fuse wire has to be changed whenever it melts.
- Hence, I appreciate the MCB for protecting home appliances.
Question 9.
What is series connection of devices? What happens if any one of the devices is removed?
Answer:
- If the second terminal of the first device is connected to the first end of the second device, such type of connection is called series connection.
- In series connection electricity has only one path.
- If any of them is removed or not functioning properly, it becomes an open circuit.
Question 10.
What is parallel connection of devices ? What is its advantage?
Answer:
- If all the first terminals of all the devices are connected to one point and all the second terminals are connected to another point such type of connection is called parallel connection.
- In parallel connection electricity has more than one path.
- Even if any one of them is removed the circuit remains closed.
Question 11.
How does the brightness of the bulb changes, if a number of cells are connected 0 in series ii) in parallel?
Answer:
i) If a number of cells are connected in series the brightness of the bulb is enhanced,
ii) If a number of cells are connected in parallel the brightness of the bulb remains same (or) does not change.
Question 12.
Why the batteries in a torch light are connected in series?
Answer:
- If we connect batteries/cells in series it enhance the brightness of the bulb, the batteries in a torch light are connected in series.
- So, to enhance the brightness of the bulb.
Question 13.
How does the brightness of the bulb change when a number of bulbs are connected in i) series ii) parallel?
Answer:
i) If a number of bulbs are connected in series the brightness of the bulb is reduced.
ii) If the number of bulbs are connected in parallel, the brightness of the bulb remains same.
Question 14.
How does an electric-iron box work?
Answer:
- The electric iron box contain a coil of wire, which is generally made up of Nichrofne.
- This coil of wire is called a filament, which produce heat, when current is passed through it.
Question 15.
How does a bulb with filament glow?
Answer:
- When electric current is passed through the filament (made with Tungsten), it becomes red hot and further becomes bright white.
- This bright white glow of the filament gives light.
Question 16.
What happens if we pass current through the copper coil around a nail?
Answer:
The nail acts as a magnet, when current is passed through the coil around it.
Question 17.
Are electro-magnets permanent magnets? Justify your answer.
Answer:
- Electromagnets are not permanent magnets.
- Because, they lose the property of magnetism when the circuit is open.
Question 18.
Write some situations which lead to an electric shock.
Answer:
- Operating a switch with a wet hand.
- Removing plug pins when the switch is on.
- Using wires without insulation.
- Changing bulb when the switch is on.
- Holding a person with a current shock.
Question 19.
What immediate action should we take to save a person who gets electric shock?
Answer:
- When anybody gets an electric shock.
- First, cut off the power supply.
- If it is not possible, push away the person with a dry stick.
- If the shock is severe and the person is unconscious, give mouth to mouth artificial respiration.
- Sometimes heart beat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered. This is called Cardio Pulmonary Resuscitation (CPR). Immediately take him to the hospital.
Question 20.
What is ISI? What is its use?
Answer:
- ISI means Indian Standards Institution.
- It can be observed on the electrical devices.
- The ISI mark ensures the quality of appliances and safety of users.
Question 21.
When the power to house cut off, the Saritha noticed that her father was changing the fuse wire. Then she had many doubts. What would be those doubts?
Answer:
- What is fuse?
- How does it work?
- What happens to the fuse, when current is cut off?
- What is the use of fuse?
Question 22.
Filament bulbs are hot, but some other bulbs like LED, CFL are cold. Guess, what is the reason?
Answer:
- Filament bulbs are made up of Tungsten filaments.
- These are working on the principle of heating effect of the electricity.
- So, they are hot.
- But, other bulbs like CFL and LED are not working on this principle. Hence they are cool.
Question 23.
Guess, what would happen if home appliances were connected in a series connection?
Answer:
- If one device is stopped or failed to work, all other devices will also stop.
- If one device is switched on the other devices will also works.
Question 24.
Write the procedure of making of our own cell.
Answer:
- Take a lemon and insert a zinc plate and a copper plate into it.
- These plates acts as electrodes and the juice inside the fruit acts as electrolyte.
- Connect two terminals of the bulb to zinc and copper plates using connecting wires.
- The bulb will glow.
Question 25.
Write the required materials to do an activity to know about heating effect of electric current.
Answer:
- Electric cell,
- Iron nails – 2,
- Wooden board,
- Connecting wires,
- 10 cm of Nichrome wire etc.
Question 26.
Write the material required to make a electromagnet.
Answer:
Battery, Switch, Iron nail, Insulated copper wire, and small pins.
Question 27.
What happens if the switch is open in the experiment of given picture.
Answer:
When we switched off the circuit, immediately all the pins fall from the iron nail.
Question 28.
Observe the diagram and write answers to the given questions.
1) Which bulb is more power saver?
2) Which bulb has less life span?
3) Which bulb do you suggest for your home?
4) Which bulb works on the principle of heating effect of electricity?
Answer:
- LED
- Incandescent
- LED
- Incandescent.
Question 29.
Fill in the table with suitable answers.
Name of the Device | Use |
To give light | |
Switch | |
To protect from high voltage | |
Cell |
Answer:
Name of the Device | Use |
Bulb | To give light |
Switch | To open or close a circuit |
Fuse | To protect from high voltage |
Cell | To given electricity |
Question 30.
Observe the following circuit diagrams and answer the question.
What difference do you find between diagrams A and B?
Answer:
We observe that the bulb in circuit A is not glowing and in circuit B it is glowing.
We can also see the switch is in OFF mode in circuit diagram A and it is in ON mode in circuit diagram B. Circuit diagram A represents open circuit, where as circuit diagram B represents closed circuit.
Question 31.
Observe the figure and give answers to the questions.
1) How are the cells connected?
2) If one of the cells is disconnected what will happen?
Answer:
- Cells are connected in parallel.
- The bulb will glow as usual if one of the cells is disconnected.
Question 32.
Draw the given diagram by using symbols instead of realistic components.
Answer:
Question 33.
Draw the diagram of setup of material in make a cell with lemon.
Answer:
Question 34.
Draw the diagram of a simple circuit.
Answer:
Question 35.
Draw a circuit diagram showing the parallel connection of the cells.
Answer:
Question 36.
Draw a circuit diagram showing the series connection of the cells.
Answer:
37. Draw a circuit diagram showing the parallel connection of bulbs.
Answer:
38. Draw a circuit diagram showing the series connection of bulbs.
Answer:
39. Draw a device alignment diagram of equipment in the experiment of heating effect of electric current.
Answer:
40. Draw the diagram showing the arrangement of circuit to make an electromagnet.
Answer:
41. Draw the symbol of ISI mark.
Answer:
42. Where do we use dry cells? What are its advantages?
Answer:
- In our daily life we use dry cells in torch lights, wall clocks, radios etc.
- Dry cell consists of an electrolyte in dried form.
- So, it is easy to move anywhere.
Question 43.
How does a switch work in a circuit?
Answer:
- We know that switch Is used to open or dose a circuit
- When the switch is ‘off’ position, bulb does not glow, because the circuit Is opened.
- If we keep the switch in ‘on’ mode, the circuit is closed and the bulb glows.
Question 44.
How do circuit diagrams help to electricians?
Answer:
- A circuit diagrams is a graphic representation of an electric circuit
- It shows how the electric components are connected together.
- Electricians and engineers draw circuit diagrams to help them design the actual circuits.
Question 45.
What is the first aM few electric shock?
(OR)
How do you perform CPR?
Answer:
- It the electric shock is severe and the person is unconscious, given mouth to mouth artificial respiration.
- Sometimes heartbeat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered, this is called Cardio Pulmonary Resuscitalion (CPR)
Question 46.
How do you check for the good electric appliances?
Answer:
While selecting electric appliances:
- Check ISI (Indian Standard institution) mark on all electrical appliances before you buy.
- Check for more star rating.
7th Class Science 6th Lesson Electricity Long Questions and Answers
Question 1.
What is a cell? How does it work?
Answer:
A cell is a device used to generate electricity. It mainly consists of two components.
- Electrolyte – This is a chemical component that conducts the electricity.
- Electrodes – There are two electrodes in a ceiL One is positive electrode called anode and the other is negative electrode called cathode.
When electrodes come in contact with electrolyte, a chemical reaction takes place inside the cell to produce electricity. Thus, it converts the chemical energy into electrical energy When electrodes are connected to the wires in a circuit, electricity passes through them.
Question 2.
What is a both? Write different types of bain How does an Incandescent bulb work? Does if save Are electrical energy?
Answer:
- Bulb is an electric device which converts electrical energy into light energy.
- There are different types at bulbs. They are 1) incandescent bulb, 2) Fluorescent bulb (Tube light), 3) CFL (Compact Fluorescent Lamp), 4) LED bulb, etc.
- Incandescent bulb works on the principle of heating effect of electricity.
- Incandescent bulb doesn’t save electrical energy. It consumes more electrical energy compared to CFL and LED lamps.
Question 3.
Write the differences between series and parallel connections of cells.
Answer:
Series connection | Parrllel connection |
I) If the second terminal of the first device is connected to the first end of the second device such type of connection is called series connection. | 1) If all the first terminals of all the devices are connected to one point and all the second terminals are cennected to another point, such type of connection is called of parallel connection. |
2) In series connection, electricity has only one path. | 2) In parallel connection electricity has more than one path. |
3) If any one of the cells is removed or not functioning properly it becomes an open circuit. | 3) Even if anyone of them is removed the circuit remains closed.
|
4) In series brightness of the bulb is enhanced. | 4) In parallel connection bulb will glow as usual. |
5) We can use series connection of cells in torch lights, toys, remotes, wall clocks etc. | 5) We can use parallel connection of cells for a long lasting battery life. |
Question 4.
Write the differences between series and parallel connections of bulbs.
Answer:
Series connection of bulbs | Parallel connections of bulbs |
1) In series connection electricity has only one path. | 1) In parallel connection electricity has more than one path. |
2) If one of the bulbs is removed or broken, the circuit becomes open, and the otter bulbs will not glow. | 2) If one of tie bulbs is removed or broken, the circuit remains same and the busib will j glow as usual. |
3) The brightness of the bciib is reduced in series connection. | 3) The brightness erf the bulb remains same in parallel connection. |
4) Series eettnectioo of btsifes is used for decorative purpose. | 4) FaraEei coaraeetkm of bulbs is used in household connection. |
Question 5.
Explain the following :
a) Heating effects of electric current.
b) Magnetic effects of electric current.
Answer:
a) Heating effects of electric current:
- The production of heart due to the flow of electricity through a wire is called heating effects of electricity.
- Electric devices like electric stoves, room heaters, iron boxes, electric kettles, electric cookers, heaters, geysers, hair dryers work on the principle of heating effects of electric current.
- All these appliances contain a heating element is called a filament.
- Generally, a filament is made up of Nichrome in iron boxes and the filaments of an electric bulb is made of Tungsten.
b) Magnetic effects of electric current:
- The production of magnetic force due to the flow of electricity through a wire is called magnetic effect of electricity.
- The devices which act as magnets when electricity passes through them are called electromagnets.
- The electric devices like loudspeakers, fan, bell, motor, mixer grinders, MRI machines, generators, metal detectors, mobile phones work on the principle of magnetic effect of electricity.
- Magnetic effects produced in a coil which is wound around a soft iron due to the passing of electricity in the coil.
Question 6.
1) What is an electric shock?
2) Which situations lead to an electric shock?
3) What is the first aid for efectric shock?
4) How does CPR help to the person?
Answer:
1) An electric shock occurs when a person comes into contact with an electrical source. Electricity flows through a portion of the body causing a shock It leads to major damage, sometimes it may cause death.
2) i) Operating a switch with a wet hand.
ii) Removing plug pins when the switch is on.
iii) Using wires without insulation.
iv) Changing bulb when the switch is on.
3) i) When anybody gets an electric shock.
ii) First, cut off the power supply.
iii) If it is not possible, push away the person with a dry stick.
iv) If the shock is severe and the person is unconscious, give mouth-to-mouth artificial respiration.
4) Sometimes heart beat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered. This is called Cardio Pulmonary Resuscitation (CPR). Immediately take him to the hospital.
Question 7.
Fill in the table with suitable answers.
Answer:
Question 8.
Observe the given figures and answer the following questions.
Answer:
1) In which circuit bulbs are connected in parallel?
2) In which circuit electricity passes through only one path?
3) Which circuit represents household connections?
4) What happens if one bulb is damaged in circuit A?
5) In which circuit glow of bulb is enhanced?
Answer:
- Circuit B
- Circuit A
- Circuit B
- Circuit will be opened
- Circuit A
Question 9.
Fill in the table.
Name of the device | Magnetic effect of electricity | Heating effect of electricity |
1. Electric stove | ✗ | ✓ |
2. Electric iron box | ||
3. Electric fan | ||
4. Electric bell | ||
5. Metal detector | ||
6. Loud speaker | ||
7. Filament bulb | ||
8. Electric kettle | ||
9. Geyser |
Answer:
Name of the device | Magnetic effect of electricity | Heating effect of electricity |
1. Electric stove | ✗ | ✓ |
2. Electric iron box | ✗ | ✓ |
3. Electric fan | ✓ | ✗ |
4. Electric bell | ✓ | ✗ |
5. Metal detector | ✓ | ✗ |
6. Loud speaker | ✓ | ✗ |
7. Filament bulb | ✗ | ✓ |
8. Electric kettle | ✗ | ✓ |
9. Geyser | ✗ | ✓ |
Question 10.
Draw the diagram of a dry cell and label the parts.
Answer:
Question 11.
Draw the symbols of given electrical components.
1) Cell 2) Battery 3) Bulb 4) Glowing bulb 5) Switch in ‘ON’ mode 6) Switch in ‘OFF’ mode 7) Fuse 8) Connecting wires.
Answer:
Question 12.
Here a circuit with real components are given. Draw the circuit by using symbols of the components.
Answer:
Answer:
Question 13.
Kalyan uses 5 LED bulbs of 9W for 10 hours, 3 fans of 60 W for 8 hours, 1 TV of 100 W for 6 hours in his house per day. Calculate the cost of his consumed electricity for a month at the rate of ₹ 10 per unit.
Answer:
Problems Given In The Lesson
Exercise – 1
The meter reading in Chandu’s house for the month of December 2020 is 29171 units. The meter reading in the previous month is 29062 units. Calculate how much he has to pay towards electricity bill in December. The unit cost is Rs.3.16.
Answer:
Reading in December | 29171 units |
Reading in previous month | 29062 units |
No. of units of electricity consumed | 109 units |
Cost per unit | Rs.3.16 |
Amount to be paid | 109 x 3.16= Rs.344.44 ( Rs.344 only) |
Exercise – 2
Suppose in a house there are 5 bulbs of 100W each, five of 60 W each, five of 40W each. All of them are used for five hours everyday. How many units of electricity is used in the month of February 2021? How much will they have to pay at Rs.2.80/- per unit?
Answer:
AP Board 7th Class Science 6th Lesson 1 Mark Bits Questions and Answers Electricity
I. Multiple Choice Questions
1. The positive electrode in a cell is called
A) Electrolyte
B) Anode
C) Cathode
D) Filament
Answer:
B) Anode
2. Which of the following converts chemical energy into electrical energy?
A) Cell
B) Bulb
C) Fan
D) Switch
Answer:
A) Cell
3. The container of a dry cell works as
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
B) Cathode
4. A carbon rod with a metal cap in a cell works as
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
A) Anode
5. Generally the chemical used in a dry cell is
A) Copper sulphate
B) Sodium chloride
C) Ammonium chloride
D) Potassium hydride
Answer:
C) Ammonium chloride
6. The lemon juice in a cell is acts as a
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
C) Electrolyte
7. Dry cell is not used in
A) Torch light
B) Wall clock
C) Radio
D) Mobiles
Answer:
D) Mobiles
8. Assertion (A) : Dry cell is easy to move any where.
Reason (R) : Dry cell consists of also electrolyte in dried form.
A) A and R are correct and R is a correct reason to A
B) A and R are correct but R is not a correct reason to A
C) A is correct but R is incorrect
D) A is incorrect but R is correct
Answer:
A) A and R are correct and R is a correct reason to A
9. Generally, button cells are used in
A) Torch lights
B) Mobile phones
C) Wrist watches
D) Vehicles
Answer:
C) Wrist watches
10. 1) When switch is in ‘off position the circuit is a closed.
2) When switch is in’off position the bulb does not glow.
A) 1 is correct
B) 2 is correct
C) 1 and 2 are correct
D) 1 and 2 are wrong
Answer:
B) 2 is correct
11. Which of the following consumes more power than others?
A) Incandescent bulb
B) Fluorescent bulb
C) CFL
D) LED
Answer:
A) Incandescent bulb
12. Fuse wire is made of
A) Low melting point wire
B) High melting point wire
C) No melting point wire
D) A or B
Answer:
A) Low melting point wire
13. Which of the follow device prodect the electrical home appliances?
A) Fuse
B) MCB
C) A and B
D) Filament
Answer:
C) A and B
14. A siaifsie decftfc circuit amwBlmg of
A) a battery
B) a bulb
C) a switch
D) above all
Answer:
D) above all
15. This is the symbol of
A) a cell
B) a battery
C) two switches
D) fuse
Answer:
B) a battery
16. This symbol represents
A) a cell
B) an open switch
C) a closed switch
D) an open cell
Answer:
B) an open switch
17. WMADftefofloif mg represents a glowing bulb?
Answer:
A
18. On series connection has
A) Only two paths
B) Only one path
C) More than one path
D) None
Answer:
B) Only one path
19. If a number of cells are connected in series the brightness of the bulb is
A) Enhanced
B) Reduced
C) As usual
D) A or B
Answer:
A) Enhanced
20. If a number of cells are connected in parallel the brightness of the bulb is
A) Enhanced
B) Reduced
C) As usual
D) A or B
Answer:
C) As usual
21. In which connection one of the cells are removed the circuit does not open?
A) Series
B) Parallel
C) A and B
D) None
Answer:
B) Parallel
22. If a number of bulbs are connected in series the brightness of the bulb is
A) Enhanced
B) Reduced
C) Sanafe issmre
D) Aor B
Answer:
B) Reduced
23. If a number of bulbs are connected in parallel the brightness of the bulb is
A) Enhanced
B) Reduced
C) Remains same
D)A or B
Answer:
C) Remains same
24. Household devices are connected in
A) Series
B) Parallel
C) A or B
D) None
Answer:
B) Parallel
25. Which of the following gives light by glowing in Bulbs?
A) Nichrome
B) Tungsten
C) Alnico
D) Copper
Answer:
B) Tungsten
26. Generally filament in iron boxes are made up of
A) Nichrome
B) Tungsten
C) Alnico
D) Copper
Answer:
A) Nichrome
27. The devices which acts as magnets when electricity passes through them
A) Electric kettles
B) Electric heaters
C) Electromagnets
D) MCB
Answer:
C) Electromagnets
28. Which of the following works on principle of magnetic effect of electricity?
A) Electric rice cooker
B) Thermometer
C) Electric bell
D) Electric bulb
Answer:
C) Electric bell
29. Which of the following is required to make an electromagnet?
A) Coiled copper wire
B) Nail
C) Electricity
D) Above all
Answer:
D) Above all
30. Which of the following property can levitate a magnetic object?
A) Heat effect of electricity
B) light effect of electricity
C) Chemical effect of electricity
D) Magnetic effect erf etedtricity
Answer:
D) Magnetic effect erf etedtricity
31. Electromagnets are
A) permanent magnets
B) temporary msassets
C) not the magnets
D) bad conductors
Answer:
A) permanent magnets
32. 1 kilo watt =
A) 1000 watts
B) 100 watts
C) 1/1000 watts
D) 1/100 watts
Answer:
A) 1000 watts
33. 1 unit of electricity means
A) 1 WH
B) 1 KWH
C) 1000 KWH
D) 1/1000 KWH
Answer:
B) 1 KWH
34. Immediate action to be tacken when an electric shock occurs is
A) pouring erf water
B) danger with the device
C) Cut off power supply
D) Expiry date of the device
Answer:
C) Cut off power supply
35. Indicates
A) Power saving erf the device
B) Danger with the device
C) Quality erf the device
D) Expiry date of the device
Answer:
C) Quality erf the device
II. Fill in the blanks
1. …………………. is a device used to generate electricity
2. The chemical componesrf that conducts electricity is called …………………. .
3. The negative electrode is called …………………. .
4. The …………………. electrode is called anode.
5. A cell converts the …………………. energy into …………………. energy.
6. The positive and negative terminals are called …………………. .
7. A group of …………………. is called a battery.
8. When switch is in ‘ON’ mode, the circuit is …………………. .
9. An ordinary bulb gives …………………. and …………………. .
10. CFL means …………………. .
11. LED means …………………. .
12. The electrical appliance with more stars consumes …………………. electricity.
13. …………………. protects home appliances from the excess of electricity flows through them.
14. Generally, fuse wire made of …………………. melting point.
15. MCB means …………………. .
16. …………………. is better, when compared to electric fuse.
17. A …………………. is a graphical representation of an electrical circuit.
18. The electrical symbol of fuse is …………………. .
19. In …………………. connection of cells life of battery increases.
20. Nichrome wire gets …………………. when electricity passed through it.
21. The production of …………………. due to the flow of electricity through a wire is called heating effect of electricity.
22. Household electricity is measured in …………………. .
23. 1 …………………. = 1000 watts.
24. KWH means …………………. .
25. A …………………. occurs when a person comes into contact with an electrical source.
26. Electricity flows through a portion of the body causing a
27. CPR means …………………. .
28. ISI means …………………. .
29. ISI mark ensures …………………. of the appliances.
Answer:
- A cell
- Electrolyte
- Cathode
- positive
- chemical, electrical
- electrodes
- cells
- closed
- heat, light
- Compact Fluorescent Lamp
- Light Emitting Diode
- less
- Fuse
- Low
- Miniature Circuit Breaker
- MCB
- circuit diagram
- parallel
- heated up
- heat
- KWH or units
- kilo watt
- kilo watt hour
- Electric
- shock
- Cardio Pulmonary Resuscitation
- Indian Standards Institutions
- quality
III. Match the following
1.
Group – A | Group – B |
A) Electrolyte | 1) Copper |
B) Electrode | 2) Nichrome |
C) Filament | 3) Ammonium chloride |
D) Connecting wire | 4) Carbon rod |
E) Cell | 5) Lithium – ion |
Answer:
Group – A | Group – B |
A) Electrolyte | 3) Ammonium chloride |
B) Electrode | 4) Carbon rod |
C) Filament | 2) Nichrome |
D) Connecting wire | 1) Copper |
E) Cell | 5) Lithium – ion |
2.
Group – A | Group – B |
A) Dry cell | 1) Bikes |
B) Lithium cell | 2) Wrist watches |
C) Button cell | 3) Torches |
D) Alkaline cell | 4) Mobiles |
Answer:
Group – A | Group – B |
A) Dry cell | 3) Torches |
B) Lithium cell | 4) Mobiles |
C) Button cell | 2) Wrist watches |
D) Alkaline cell | 1) Bikes |
3.
Group – A | Group – B |
A) Cell | 1) Protects home appliances |
B) Bulb | 2) Opens or closes circuits |
C) Fuse | 3) Produces light |
D) Switch | 4) Produces electricity |
E) Iron box | 5) Produces heat |
F) Cranes | 6) Produce magnetism |
Answer:
Group – A | Group – B |
A) Cell | 4) Produces electricity |
B) Bulb | 3) Produces light |
C) Fuse | 1) Protects home appliances |
D) Switch | 2) Opens or closes circuits |
E) Iron box | 5) Produces heat |
F) Cranes | 6) Produce magnetism |
4.
Answer:
A – 7, B – 3, C – 1, D – 5, E – 6, F – 2, G – 4.
Do You Know?
→ In 1752, Franklin conducted the kite experiment to show that lightning was also electricity. He flew a kite during a thunderstorm. He tied a metal key to the string of the kite to conduct the electricity.
→ LED (Light Emitting Device) has two legs. Long leg indicates positive(+ve) and short leg indicates negative (-ve). Early LEDs produced only red light, but modern LEDs can produce several different colors, including red, green and blue light. LEDs are used as indicators in mobiles, laptops, T.V remotes etc.
→ A switch can be placed anywhere in the circuit and a cell can be connected in any direction in the electric circuit.
→ The scientist Oersted discovered that a magnetic field is produced around a current carrying conductor. Electromagnets are made by using the relationship between electricity and magnetism.
→ Michael Faraday made a magnet to revolve around a coil of wire which produced electricity. He invented electric generator or dynamo and transformer.