CBSE 7th Standard Science Electric Current and Effects Important Questions And Answers Study Material - QB365 Set E | QB365

7th Standard CBSE Syllabus & Materials

7th Standard CBSE

CBSE 7th Social Science Theme E - Understanding Market - New Sample Question Papers Study Material - QB365 Set A

NEW

7th Standard CBSE

CBSE 7th Social Science Theme E - From Barter to Money - New Sample Question Papers Study Material - QB365 Set A

NEW

7th Standard CBSE

CBSE 7th Social Science Theme D - The Constitution of India- An Introduction - New Sample Question Papers Study Material - QB365 Set A

NEW

7th Standard CBSE

CBSE 7th Social Science Theme D - From the Rulers to the Ruled : Types of Governments - New Sample Question Papers Study Material - QB365 Set A

NEW

7th Standard CBSE

CBSE 7th Social Science Theme B - The Age of Reorganisation - New Sample Question Papers Study Material - QB365 Set A

NEW

7th Standard CBSE

CBSE 7th Social Science Theme B - The Rise of Empires - New Sample Question Papers Study Material - QB365 Set A

CBSE 7th Standard Science Electric Current and Effects Important Questions And Answers Study Material - QB365 Set E

Published on: 31/10/2025

Question Set E

CBSE 7th Standard Science Electric Current and Effects Important Questions And Answers Study Material - QB365

Download CBSE Class 7th Standard CBSE Science question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 7th Standard CBSE Science

Questions + Answers key

Take MCQ Science Test

QB365 Student Learing Managemnet System

Std: 7th Standard CBSE - Science

chapter: Electric Current and Effects - Important Questions And Answers

Visit QB365-SLMS - https://www.qb365.in/slms/ Complete Questions and Answers

Questions:

Generic 3

5 x 3 = 15

Batteries used in tractors, trucks and inverters are also made from cells. Then why it is called a battery?

Explain the following.
(a) Copper and aluminium wires are usually employed for electricity transmission. Explain the reason.
(b) Explain how does the resistance of a wire vary with its length.
(c) The tungsten is used almost exclusively for filament of electric lamp. Comment.

Explain how a battery can be constructed.

In the circuit shown in figure

(a) Would any of the bulb glow, when the switch is in the OFF position?
(b) What will be the order in which the bulbs A, B and C will glow, when the switch is moved to the ON position?

When the current is switched ON through a wire, a compass needle kept nearby gets deflected from its North-South position. Explain.

Fill up / 1 Marks

5 x 1 = 5

The core of an electromagnet is made from____________.

A combination of two or more cells is called a_____________.

Our body is a_____________of electricity.

When current is switched ON in a room heater, it____________.

10.

The combination of two or more cells is called a___________.

True or False

5 x 1 = 5

11.

Electric fuse is based on the magnetic effect of electric current.

(a)

True

(b)

False

12.

A car battery is just one big cell.

(a)

True

(b)

False

13.

When an electric current flows through a wire, it behaves like a magnet.

(a)

False

(b)

True

14.

CFLs consume more electricity than an ordinary bulb.

(a)

True

(b)

False

15.

An electromagnet does not attract a piece of iron.

(a)

True

(b)

False

Generic 2

5 x 2 = 10

16.

We should not touch the lighted bulb. Explain, why.

17.

State whether the bulb glows when the circuit is opened.

18.

Name the scientist who discovered the magnetic effect of electric current.

19.

Why is an electric fuse required in all electrical appliance?

20.

Explain why are CFLs (Compact Fluorescent Lamps) preferred over electric bulbs.

Generic 5

2 x 5 = 10

21.

Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness both of them connected with wires as shown in the circuit given in figure. The current flowing in both the circuits is the same.
(a) Will the heat produced in both the cases be equal? Explain.
(b) Will the heat produced be the same, if the wires taken by them are of equal lengths but of different thickness? Explain.

22.

One day, Pinki was ironing the clothes in her room. After half an iron of ironing, the light went off and Pinki went outside to the lobby of her house to check it there was any problem in the household circuit. At the same time, she listened the voice of her 4 years old daughter from the same room where she was ironing the clothes. Her daughter was about to touch the hot electric iron but at the same moment, Pinki entered in the room and pushed her daughter back from that place.
(a) On which effect of electric current, does the electric iron works?
(b) Mention the values showed by Pinki here.

Multiple Choice Question

5 x 1 = 5

23.

The coil of wire contained in heater is known as

(a)

circuit

(b)

component

(c)

spring

(d)

element

24.

A battery is a combination of

(a)

only single cell

(b)

only two cells

(c)

two or more cells

(d)

None of the above

25.

Which of the following precautions need not be taken while using electric gadgets/ appliances/circuit?

(a)

We should never touch a lighted electric bulb connected to the mains

(b)

We should never do experiment with the electric supply from the mains or a generator or an inverter

(c)

We should never use just any wire or strip of metal in place of a fuse

(d)

We should never turn the switch in ON position

26.

When an electric current flows through a copper wire AB as shown in figure, the wire

(a)

deflects a magnetic needle placed near it

(b)

becomes red hot

(c)

gives electric shock

(d)

behaves like a fuse

27.

Choose the statement which is not correct in the case of an electric fuse.

(a)

Fuses are inserted in electric circuits of all buildings

(b)

There is a maximum limit on the current which can safely flow through the electric circuits

(c)

There is a minimum limit on the current which can safely flow in the electric circuits

(d)

If a proper fuse is inserted in a circuit it will below off if current exceeds the safe limit

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Generic 3

5 x 3 = 15

The cell is the unit of battery when more than one cell are combined together, it forms a battery. In trucks, tractors and inverters, cells are internally arranged and we need not to connect it externally, so we called it as batteries.

(a) Due to the low resistance and strength of aluminium and coppers, both these metals are usually employed for the transmission of electricity.
(b) There is always an increase in the length of the wire with the increase In its resistance.
(c) Since tungsten has high melting point and high resistance. So, that is why, the tungsten is used exclusively for filament of electric lamp.

As we know that a battery is a combination of two or more cells and it can be constructed by placing cells property on cell holder in such a way that the positive terminal of one cell is connected to the negative terminal of other.
A piece of wire is connected to each of the two metal clips on the cells holder.

(a) Any of the bulb will not glow when the switch is in the OFF position because circuit is not complete.
(b) All the bulbs glow simultaneously as the switch is moved to the ON position.

When the current is switched ON through a wire or a coil, there is a magnetic field created around the coil or wire and we can say that the wire or coil gets magnetised. Thus, a compass needle kept nearby gets deflected from its North-South position due to other magnet formed by current carrying wire or coil.

Fill up / 1 Marks

5 x 1 = 5

()
iron

()
battery

()
good conductor

()
gets heated

10.

()
battery

True or False

5 x 1 = 5

11.

(b)
False

12.

(b)
False

13.

(a)
False

14.

(b)
False

15.

(b)
False

Generic 2

5 x 2 = 10

16.

The lighted bulb connected to main supply should not be touched by our hand directly, as a lighted bulb can be very hot and can burn our hand as well.

17.

No, the bulb does not glow when the circuit is opened. The bulb glows only when the circuit is closed.

18.

The scientist who discovered the magnetic effect of electric current is Hans Christian Oersted.

19.

Electric fuse is required in all electrical appliances to prevent damage from excessive current flow and during short circuit.

20.

Compact fluorescent lamps are preferred over electric bulbs because electric bulbs use more power of electricity and it also losses electrical energy in the form of heat but it is not so in compact fluorescent lamps.

Generic 5

2 x 5 = 10

21.

(a) No, the amount of heat produced in both the wires will be different because amount of heat produced in a wire on passing electric current depends on the length of wire and here length is different for both the wires.
(b) No, the amount of heat produced in the wire of same length but different thickness cannot be same because amount of heat produced in a wire also depends on the thickness of the wire.

22.

(a) The electric iron works on the basis of heating effect of electric current.
(b) The values showed by Pinki here is a great concern and love towards her own 4 years old daughter.

Multiple Choice Question

5 x 1 = 5

23.