NCERT Class VII Science Solutions: Chapter 14-Electric Current and Its Effects Part 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 1:

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

  1. Deflects a magnetic needle placed near it.
  2. Becomes red hot.
  3. Gives electric shock.
  4. Behaves like a fuse.
As Showing in Images is a Electric Current Flows through a C …

Answer: A

Question 2:

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

  1. Fuses are inserted in electric circuits of all buildings.
  2. There is a maximum limit on the current which can safely flow through the electric circuits.
  3. There is a minimum limit on the current which can safely flow in the electric circuits.
  4. If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.

Answer: C

Electric Fuse

Question 3:

Three bulbs A, B, C are connected in a circuit as shown in Figure When the switch is ‘ON’

  1. Bulb C will glow first.
  2. Bulb B and C will glow simulaneously and bulb A will glow after some time.
  3. All the bulbs A, B and C will glow at the same time.
  4. The bulbs will glow in the order A, B and C.
As Showing in Images is a Three Bulbs Are Connected in a Cir …

Answer: C

Question 4:

When a switch is in OFF position.

  1. Circuit starting from the positive terminal of the cell stops at the switch.
  2. Circuit is open.
  3. No current flows through it.
  4. Current flows after some time.

Choose the combination of correct answer from the following.

  1. all are correct
  2. (ii) and (iii) are correct
  3. Only (iv) is correct
  4. Only (i) and (ii) are correct

Answer: B

Question 5:

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

  1. We should never touch a lighted electric bulb connected to the mains.
  2. We should never experiment with the electric supply from the mains or a generator or an inverter.
  3. We should never use just any wire or strip of metal in place of a fuse.
  4. We should never turn the switch in ON position.

Answer: D