Electro Magnetic Induction And Alternating Currents Question 455

Question: Magnetic flux linked with a stationary loop of resistance R varies with respect to time during the time period T as follows: $ \phi =at(T-t) $ The amount of heat generated in the loop during that time (inductance of the coil is negligible) is

Options:

A) $ \frac{aT}{3R} $

B) $ \frac{a^{2}T^{2}}{3R} $

C) $ \frac{a^{2}T^{2}}{R} $

D) $ \frac{a^{2}T^{3}}{3R} $

Show Answer

Answer:

Correct Answer: D

Solution:

  • Given that $ \phi =at(T-t) $

    Induced emf, $ E=\frac{d\phi }{dt}=\frac{d}{dt}[at(T-t)] $ = at $ (0-1)+a(T-t)=a(T-2t) $

    So, induced emf is also a function of time.

    $ \therefore $ Heat generated in time T is $ H\int\limits_{0}^{T}{\frac{E^{2}}{R}}dt=\frac{a^{2}}{R}\int\limits_{0}^{T}{{{(T-2t)}^{2}}} $

    $ dt=\frac{a^{2}T^{3}}{3R} $



NCERT Chapter Video Solution

Dual Pane