A capacitor is made of two circular plates each of radius \(12~\text{cm}\) and separated by 5.0 cm. The capacitor is being charged by an external source. The charging current is constant and equal to 0.15 A. The displacement current across the plates is:

1. 0

2. 0.14 A

3. 0.16 A

4. 0.15 A

A parallel plate capacitor made of circular plates each of radius \(R=6.0\) cm has a capacitance \(C=100\) pF. The capacitor is connected to a \(230\) V AC supply with an (angular) frequency of \(300\) rad/s. The amplitude of \(\vec{B}\) at the point \(3\) cm from the axis between the plate is:

       
1. \(1.12\times 10^{-11}\) T
2. \(2.01\times 10^{-12}\) T
3. \(1.63\times 10^{-11}\) T
4. \(1.01\times 10^{-12}\) T

A plane electromagnetic wave travels in a vacuum along the z-direction. Then the directions of its electric and magnetic field vectors will be:

A radio can tune in to any station in the \(7.5\) MHz to \(12\) MHz bands. What is the corresponding wavelength band?
1. \(40\) to \(25\) m
2. \(10\) to \(100\) m
3. \(50\) to \(60\) m
4. \(20\) to \(10\) m

Which physical quantity does not change in vacuum for X-rays?

The amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is \(B_0=510\) nT. What is the amplitude of the electric field part of the wave?
1. \(200\) N/C
2. \(153\) N/C
3. \(150\) N/C
4. \(510\) N/C

Suppose that the electric field amplitude of an electromagnetic wave is \(E_0 = 120~\text{N/C}\) and that its frequency is \(\nu = 50.0~\text{MHz}\)$$$$. The value of \(k\) is:
1. \(2.01~\text{rad/m}\)
2. \(1.72~\text{rad/m}\)
3. \(1.05~\text{rad/m}\)
4. \(2.41~\text{rad/m}\)

In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of $\mathrm{}$\(2.0\times 10^{10}~\text{Hz}\) and amplitude \(48~\text{V/m}\). What is the amplitude of the oscillating magnetic field?
1. \(4.2\times 10^{-8}~\text{T}\)
2. \(2.4\times 10^{-7}~\text{T}\)
3. \(3.8\times 10^{-8}~\text{T}\)
4. \(1.6\times 10^{-7}~\text{T}\)

The electric field part of an electromagnetic wave in vacuum is,
\(\vec{E}=(3.1 \mathrm{~N} / \mathrm{C}) \cos \left[(1.8~ \mathrm{rad} / \mathrm{m}) y+\left(5.4 \times 10^8 ~\mathrm{rad} / \mathrm{s}\right) \mathrm{t}\right] \hat{i}\).
What is the frequency of the wave?
1. \(5.7\times 10^{7}~\text{Hz}\)
2. \(9.3\times 10^{7}~\text{Hz}\)
3. \(8.6\times 10^{7}~\text{Hz}\)
4. \(7.5\times 10^{7}~\text{Hz}\)