Assertion (A) & Reason (B) MCQ

MCQ 11 Mark

Assertion (A) An electric bulb glass becomes hot after sometime when it is connected to an electric supply.
Reason (R) A bulb becomes hot due to the heating effect of electric current.

✓
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false
D
A is false but R is true.

Answer

Correct option: A.

Both A and R are true and R is the correct explanation of A

(A) Both A and R are true and R is the correct explanation of A
Explanation: When electric current flows, filament wire of bulb becomes red hot due to heating effect of current, which makes electric bulb hot glass after sometime

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MCQ 21 Mark

Assertion (A) In a cell, the longer line represents positive terminal and shorter line represent negative terminal.
Reason (R) A battery is a combination of two or more cells.

A
Both A and R are true and R is the correct explanation of A
✓
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false
D
A is false but R is true.

Answer

Correct option: B.

Both A and R are true but R is not the correct explanation of A.

(B) Both A and R are true but R is not the correct explanation of A.
Explanation: We can represent a cell in the form given below and the combination of two or more cells are called battery.

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MCQ 31 Mark

Assertion (A) Fuse wires have low melting point and high resistance.
Reason (R) An electric cell produces less amount of electric current.

A
Both A and R are true and R is the correct explanation of A
✓
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false
D
A is false but R is true.

Answer

Correct option: B.

Both A and R are true but R is not the correct explanation of A.

(B) Both A and R are true but R is not the correct explanation of A.
Explanation: Fuse wires have low melting point and high resistance, so that they can breaks the circuit in case if high current flow.

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MCQ 41 Mark

Assertion (A) Electromagnets are permanent magnets.
Reason (R) Magnetic strength of an electromagnet can be changed.

A
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is not the correct explanation of A.
C
A is true but R is false
✓
A is false but R is true.

Answer

Correct option: D.

A is false but R is true.

(D) A is false but R is true.
Explanation: Electromagnets are temporary magnets. Magnetic strength can be changed by
(i) increasing amount of current.
(ii) increasing number of turns in coil.

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MCQ 51 Mark

Assertion (A) Wire gets hot when electric current passes through it.
Reason (R) It is due to the resistance in the wire.

✓
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is the not the correct explanation of A
C
A is true but R is false
D
A is false but R is true

Answer

Correct option: A.

Both A and R are true and R is the correct explanation of A

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MCQ 61 Mark

Assertion (A) When an electric current flows through a wire, it behaves like a magnet.
Reason (R) It is due to the heating effect of electric current.

A
Both A and R are true and R is the correct explanation of A
B
Both A and R are true but R is the not the correct explanation of A
✓
A is true but R is false
D
A is false but R is true

Answer

Correct option: C.

A is true but R is false

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Science Assertion (A) & Reason (B) MCQ

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