In a plane EM wave, the electric field oscillates sinusoidally at a frequency of \(2.5\times 10^{10}~\text{Hz}\) and amplitude \(480\) V/m.  The amplitude of the oscillating magnetic field will be:
1. \(1.52\times10^{-8}~\text{Wb/m}^2\)
2. \(1.52\times10^{-7}~\text{Wb/m}^2\)
3. \(1.6\times10^{-6}~\text{Wb/m}^2\)
4. \(1.6\times10^{-7}~\text{Wb/m}^2\)

The energy density of the electromagnetic wave in vacuum is given by the relation:

1. $\frac{1}{2}.\frac{E^2}{{\epsilon }_0}+\frac{B^2}{2{\mu }_0}$ 

2. $\frac{1}{2}{\epsilon }_0{E}^2+\frac{1}{2}{\mu }_0{B}^2$

3. $\frac{E^2+B^2}{C}$

4. $\frac{1}{2}{\epsilon }_0{E}^2+\frac{B^2}{2{\mu }_0}$

A lamp radiates power \(P_0\) uniformly in all directions. The amplitude of electric field strength \(E_0\) at a distance \(r\) from it is:
1. \(E_{0} = \frac{P_{0}}{2 \pi\varepsilon_{0} cr^{2}}\)
2. \(E_{0} = \sqrt{\frac{P_{0}}{2 \pi\varepsilon_{0} cr^{2}}}\)
3. \(E_{0} = \sqrt{\frac{P_{0}}{4 \pi\varepsilon_{0} cr^{2}}}\)
4. \(E_{0} = \sqrt{\frac{P_{0}}{8 \pi\varepsilon_{0} cr^{2}}}\)

The intensity of visible radiation at a distance of \(1\) m from a bulb of \(100\) W which converts only \(5\%\) of its power into light, is:
1. \(0.4\) W/m²
2. \(0.5\) W/m²
3. \(0.1\) W/m²
4. \(0.01\) W/m²

On an EM wave, the amplitude of electric and magnetic fields are 100 v/m and 0.265 A/m.  The maximum energy flow is

(1) 26.5 $W/m^2$           (2) 46.7 $W/m^2$

(3) 66.5 $W/m^2$            (4) 86.5 $W/m^2$

The most penetrating radiation out of the following is: 

(1) X-rays        (2) $\beta$-rays            (3) $\alpha$-rays           (4) $\gamma$-rays

1. \(A\) and \(B\) only
2. B and \(C\) only
3. \(A,B,\) and \(C\) only
4. \(B\) only

The magnetic field in a plane EM wave traveling in the positive x-direction is given by 

$\mathrm{B}=\left(100\mathrm{\mu T}\right) \sin \left[\right(2\times {10}^{15}{\mathrm{s}}^{-1}\left)\right(\mathrm{t}-\mathrm{x}/\mathrm{c}\left)\right]\hat{\mathrm{j}}$

The equation for electric field is :

1. E=100sin [(2$\times {10}^{15}{s}^{-1})$(t-x/c)]$\left(-\hat{k}\right)$

2. E=(3$\times {10}^{10} \mu V/m$)sin [(2$\times {10}^{15}{s}^{-1})$(t-x/c)]$\left(-\hat{k}\right)$

3. E=3$\times {10}^{10}$sin [(2$\times {10}^{15}{s}^{-1})$(t-x/c)] $\hat{k}$

4. E=100sin [(2$\times {10}^{15}{s}^{-1})$(t-x/c)] $\hat{k}$

Statement I: A changing electric field produces a magnetic field.

Statement II: A changing magnetic field produces an electric field.

(1) If both statement-I and Statement-II are true, and Statement-II is the correct explanation of Statement-I.

(2) If both Statement-I and Statement-II are true but Statement-II is not the correct explanation of Statement-I.

(3) If Statement-I is true but Statement-II is false.

(4) If Statement-I is false but Statement-II is true.

Statement-I: Gamma rays are more energetic than X-rays.

Statement-II: Gamma rays are of nuclear origin but X-rays are produced due to sudden deceleration of high energy electrons while falling on a metal of high atomic number.

(1) If both statement-I and Statement-II are true, and Statement-II is the correct explanation of Statement-I.

(2) If both Statement-I and Statement-II are true but Statement-II is not the correct explanation of Statement-I.

(3) If Statement-I is true but Statement-II is false.

(4) If Statement-I is false but Statement-II is true.