CBSE Class 12 · 2024 · Current ElectricityMultiple Choice

An ammeter and a voltmeter are connected in series to a battery, their readings being

A

and

V

respectively. If a resistor is now connected in parallel with the voltmeter, then:

(A) $A$ will increase, $V$ will decrease✓ Correct
(B) $A$ will decrease, $V$ will increase
(C)both $A$ and $V$ will decrease
(D)both $A$ and $V$ will increase

Answer: (A)

Solution

Placing a resistor in parallel with the voltmeter lowers the resistance of that section, so the total circuit resistance falls and the current (ammeter reading

A

) increases. The larger current means a larger drop across the ammeter and the rest of the circuit, leaving a smaller potential difference across the parallel (voltmeter) section, so

V

decreases.

CBSE Class 12 Board · 2024 · Single correct option

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