Physics · 2020
JEE Main · 4 September 2020, Shift 2 · Q15
A series L - R circuit is connected to a battery of emf V. If the circuit is switched on at t =0, then the time at which the energy stored in the…
A series $\displaystyle \mathrm{L}-\mathrm{R}$ circuit is connected to a battery of emf V. If the circuit is switched on at $\displaystyle \mathrm{t}=0$, then the time at which the energy stored in the inductor reaches $\displaystyle \left(\frac{1}{\mathrm{n}}\right)$ times of its maximum value, is :
Official answer
(3)
$\displaystyle \frac{\mathrm{L}}{\mathrm{R}} \ln \left(\frac{\sqrt{\mathrm{n}}}{\sqrt{\mathrm{n}}-1}\right)$
More from Electromagnetic Induction
- For the given circuit the current through battery of 6 V just after closing the switch 'S' will be \ \ \ \ A.2022
- A conducting bar of length L is free to slide on two parallel conducting rails as shown in the figure Two resistors R_1 and R_2 are connected across…2021
- A square loop of side 10 cm and resistance 0.7 Ω is placed vertically in east-west plane. A uniform magnetic field of 0.20 T is set up across the…2024
- Regarding self-inductance: A. The self-inductance of the coil depends on its geometry. B. Self-inductance does not depend on the permeability of the…2025
- A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity 5 rad s^-1.…2022
- Two concentric and coplanar circular coils have radius a and b(≫ a) as shown in figure. Resistance of the inner coil is R. Current in the outer coil…2021
- A circular current loop of radius R is placed inside square loop of side length L(L ≫ R) such that they are co-planar and their centers coincide. The…2026
- Three identical coils C_1, C_2 and C_3 are closely placed such that they share a common axis. C_2 is exactly midway. C_1 carries current I in…2026
JEE Main 2020 Physics question, with the answer from NTA’s final answer key. Where our answers come from.