Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 201411 AprilOnline
Exam
JEE Main
Year
2014
Date
11 April
Mode
Online
Subject
Physics
Chapter
Electromagnetic Induction

JEE Main 2014 · 11 April · Online · Physics · Electromagnetic Induction

A coil of circular cross-section having 1000 turns and 4 ~cm^2 face...

A coil of circular cross-section having 1000 turns and 4 cm24 \mathrm{~cm}^2 face area is placed with its axis parallel to a magnetic field which decreases by 10−2 Wb10^{-2} \mathrm{~Wb} m−2\mathrm{m}^{-2} in 0.01 s0.01 \mathrm{~s}. The e.m.f. induced in the coil is:

Options

  1. A400mV400 \mathrm{mV}
  2. B200mV200 \mathrm{mV}
  3. C4mV4 \mathrm{mV}
  4. D0.4mV0.4 \mathrm{mV}

Correct answer

A. 400mV400 \mathrm{mV}

Step-by-step solution

Given: No. of turns N=1000N=1000 Face area, A=4 cm2=4×10−4 m2A=4 \mathrm{~cm}^2=4 \times 10^{-4} \mathrm{~m}^2 Change in magnetic field, ΔB=\Delta \mathrm{B}=10^{-2} wbm−2\mathrm{wbm}^{-2}Time taken, t=0.01 s=10−2sect=0.01 \mathrm{~s}=10^{-2} \mathrm{sec} Emf induced in the coil e=e= ? Applying formula, Induced emf, e=−dϕdte=\frac{-d \phi}{d t}=N(ΔBΔt)Acos⁡θ=1000×10−2×4×10−410−2=400mV\begin{aligned}&=N\left(\frac{\Delta B}{\Delta t}\right)A \cos \theta\\ &=\frac{1000 \times 10^{-2} \times 4 \times 10^{-4}}{10^{-2}}=400 \mathrm{mV} \end{aligned}$$
Practice Electromagnetic Induction on Quantrex Academy →

More from Electromagnetic Induction

List-I contains four conducting loops lying in the XY plane, as shown in the figures. The… JEE Advanced 2026A 30 cm long solenoid has 10 turns per cm and area of 5 cm ^2 . The current through the… JEE Main 2026A square loop of side 2 cm is placed in a time varying magnetic field with magnitude as B… JEE Main 2026An inductor of inductance 10 mH having resistance of 100\,Ω is connected to battery of… JEE Main 2026A metal rod of length L rotates about one end at origin with a uniform angular velocity ω… JEE Main 2026A circular loop of radius 20 cm and resistance 2\ Ω is placed in a time varying magnetic… JEE Main 2026In the given circuit below inductance values of L_1 , L_2 and L_3 are same. The magnetic… JEE Main 2026A circular current loop of radius R is placed inside square loop of side length L (L >>… JEE Main 2026 Full Electromagnetic Induction list All JEE Main PYQs