CUET · PHYSICS · PYQ PAPER 2023

A moving coil galvanometer has N number of turns in the coil with area A. It carries a current I and the magnetic field is B. The torque acting on the coil is :

A \(N I B^2 A^2\)
B \(N I^2 B A\)
C \(N^2 I B A\)
D NIBA

Verified Solution

Answer & Solution

Correct Answer

(D) NIBA

Step-by-step Solution

Detailed explanation

In a moving coil galvanometer, the magnetic field is designed to be radial, ensuring the plane of the coil is always parallel to the field ( \(\theta \left.=90^{\circ}\right)\). This results in the maximum torque, given by the formula \(\tau\) = NIBAsin…

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

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Match List-I with List-II

List - I	List - II
(A) \(\sin ^{-1}(-1)\)	(I) \(\frac{5 \pi}{6}\)
(B) \(\cot ^{-1}(-1)\)	(II) \(-\frac{\pi}{2}\)
(C) \(\sec ^{-1}\left(-\frac{2}{\sqrt{3}}\right)\)	(III) \(\frac{\pi}{4}\)
(D) \(\tan ^{-1}(1)\)	(IV) \(\frac{3 \pi}{4}\)

Choose the correct answer from the options given below :

CUET 2025 Hard

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