Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 201412 AprilOnline
Exam
JEE Main
Year
2014
Date
12 April
Mode
Online
Subject
Physics
Chapter
Alternating Current

JEE Main 2014 · 12 April · Online · Physics · Alternating Current

A sinusoidal voltage V(t)=100 (500 t) is applied across a pure...

A sinusoidal voltage V(t)=100sin⁡(500t)\mathrm{V}(\mathrm{t})=100 \sin (500 \mathrm{t}) is applied across a pure inductance of L=0.02HL=0.02 \mathrm{H}. The current through the coil is:

Options

  1. A10cos⁡(500t)10 \cos (500 \mathrm{t})
  2. B−10cos⁡(500t)-10 \cos (500 \mathrm{t})
  3. C10sin⁡(500t)10 \sin (500 t)
  4. D−10sin⁡(500t)-10 \sin (500 t)

Correct answer

B. −10cos⁡(500t)-10 \cos (500 \mathrm{t})

Step-by-step solution

In a pure inductive circuit current always lags behind the emf by π2\frac{\pi}{2}. If v(t)=v0sin⁡ωt\mathrm{v}(\mathrm{t})=\mathrm{v}_0 \sin \omega \mathrm{t} then I=I0sin⁡I=I_0 \sin\left(\omega t-\frac{\pi}{2}\right)Now,givenNow, givenv(t)=100 \sin (500 t)andand\mathrm{I}_0=\frac{\mathrm{E}_0}{\omega \mathrm{L}}=\frac{100}{500 \times 0.02}[\because \mathrm{L}=0.02 \mathrm{H}] I\mathrm{I}_0=10 \sin \left(500 \mathrm{t}-\frac{\pi}{2}\right)I0=−10cos⁡(500t)\mathrm{I}_0=-10 \cos (500 \mathrm{t})
Practice Alternating Current on Quantrex Academy →

More from Alternating Current

Consider a circuit consisting of a capacitor of capacitance C and a coil with N turns per… JEE Advanced 2026A LCR series circuit driven with E_ rms = 90 V at frequency f_d = 30 Hz has resistance R… JEE Main 2026A series LCR circuit with R = 20\ Ω , L = 1.6 H and C = 40\ is connected to a variable… JEE Main 2026An a.c. source of angular frequency ω is connected across a resistor R and a capacitor C… JEE Main 2026An inductor of 10 mH, capacitor of 0.1\ μ F and a resistor of 100\ Ω are connected in… JEE Main 2026The figure given below shows an LCR series circuit with two switches S_1 and S_2 . When… JEE Main 2026An inductor stores 16 J of magnetic field energy and dissipates 32 W of thermal energy… JEE Main 2026The electric current in the circuit is given as i=i_ o (t / T) . The r.m.s current for… JEE Main 2026 Full Alternating Current list All JEE Main PYQs