How are radio waves produced?

  • A
    By the rapid acceleration and deceleration of electrons in antennas.
  • B
    By the vibration of atoms in a solid.
  • C
    By the decay of radioactive nuclei.
  • D
    By the transition of electrons between energy levels in an atom.

Explore More

Similar Questions

$A$ magnetic field can be produced by

The source of a time-varying magnetic field may be:
$(A)$ A permanent magnet
$(B)$ An electric field changing linearly with time
$(C)$ Direct current
$(D)$ A decelerating charged particle
$(E)$ An antenna fed with a digital signal
Choose the correct answer from the options given below:

An alternating voltage of amplitude $40 \, V$ and frequency $4 \, kHz$ is applied directly across a capacitor of $12 \, \mu F$. The maximum displacement current between the plates of the capacitor is nearly: (in $ \, A$)

Match the following List-$I$ with List-$II$.
$A$. $\oint E \cdot dA$$(i)$ $0$
$B$. $\oint B \cdot dA$$(ii)$ $-\frac{d\phi_B}{dt}$
$C$. $\oint E \cdot dl$$(iii)$ $\frac{Q}{\varepsilon_0}$
$D$. $\oint B \cdot dl$$(iv)$ $\mu_0(i_c + i_d)$

Which of the following statements is true for displacement current?

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo