Physics · Electromagnetic Induction

JEE Main 2024 — 29 January, Shift 1 — Question 51

A square loop of side 10 cm and resistance 0.7Ω0.7 \Omega is placed vertically in east-west plane. A uniform magnetic field of 0.20 T is set up across the plane in north east direction. The magnetic field is decreased to zero in 1 s at a steady rate. Then, magnitude of induced emf is x×10−3 V\sqrt{\mathrm{x}} \times 10^{-3} \mathrm{~V}. The value of xx is \qquad .

Answer: 2

Numerical answer — enter this value.

Step-by-step solution

figure

A⃗=(0.1)2j^\vec{A}=(0.1)^{2} \hat{j}

B→=0.22i^+0.22j^\overrightarrow{\mathrm{B}}=\frac{0.2}{\sqrt{2}} \hat{\mathrm{i}}+\frac{0.2}{\sqrt{2}} \hat{\mathrm{j}}

Magnitude of induced emf e=ΔϕΔt=B→⋅A→−01=2×10−3 V\mathrm{e}=\frac{\Delta \phi}{\Delta \mathrm{t}}=\frac{\overrightarrow{\mathrm{B}} \cdot \overrightarrow{\mathrm{A}}-0}{1}=\sqrt{2} \times 10^{-3} \mathrm{~V}

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Physics
Chapter
Electromagnetic Induction
Topic
Magnetic Flux, Faraday's Law and Lenz's Law