AIIMS2018Physics-Electricity

AIIMS 2018 Physics Batteries in Parallel MCQ Question

Type: MCQ-conceptual-Medium-Class 12

Assertion : Two non-ideal batteries are connected in parallel. The equivalent emf is smaller than either of the two emfs.

Reason : The equivalent internal resistance is greater than either of the two internal resistances

A

If both assertion and reason are true and reason is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If assertion is true but reason is false.

D

If both assertion and reason are false.

Correct Answer

Option D

Detailed Explanation

In a parallel configuration of batteries, the equivalent electromotive force (emf) is determined by the battery with the highest voltage, while the internal resistance is calculated using the formula r=r1r2r1+r2r = \frac{r_1 r_2}{r_1 + r_2}, which is indeed less than either r1r_1 or r2r_2. Option (A) incorrectly suggests a formula for emf that does not apply to parallel circuits, as it implies a dependency on both battery voltages and resistances in a way that is not valid. Option (B) correctly identifies the formula for internal resistance but does not address the emf, making it incomplete. Thus, option D is the only choice that accurately reflects the principles governing parallel battery configurations.

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