Light Spectrum

Q.

What is the definition of light?

Q.

In an electromagnetic wave, the average energy density associated with the magnetic field is?

1. $\frac{{{\mathrm{Li}}_0}^2}{2}$

2. $\frac{{\mathrm{B}}^2}{2{\mathrm{\mu }}_0}$

3. $\frac{{\mathrm{\mu }}_0{\mathrm{B}}^2}{2}$

4. $\frac{{\mathrm{\mu }}_0}{2{\mathrm{B}}^2}$

Q. Gamma rays have the longest wavelength.

1. True
2. False

Q.

Which layer of the atmosphere helps in radio transmission?

Q.

Write any two examples of electromagnetic waves.

Q.

The direction of an electric field just outside the surface of a charged conductor is?

Q. Why can an x-ray telescope not based on the earth

Q.

A plane electromagnetic wave of frequency $25GHz$ is propagating in vacuum along the $z$-direction. At a particular point in space and time, the magnetic field is given by $\begin{array}{l}\overrightarrow{B}=5\times {10}^{-8}\hat{j}T\end{array}$. The corresponding electric field is given by $\begin{array}{l}\overrightarrow{E}\end{array}$ is ( speed of light $𝑐=3\times {10}^8\raisebox{1ex}{$𝑚$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$ )

1. $1.66\times {10}^{-16i}\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

2. $-1.66\times {10}^{-16i}\raisebox{1ex}{$v$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

3. $15i\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

4. $-15i\raisebox{1ex}{$V$}\!\left/ \!\raisebox{-1ex}{$m$}\right.$

Q.

Define wave with an example.

Q. The de brollies wavelength of electron travelling with 10%of velocity of light is 1 242.4pm 2. 24.2 pm 3. 2.42pm 4.0.2424pm

Q.

Can two independent sources of light be coherent?

Q. Which of the following radiation have the wavelength less than 0.3 mm?

1. Radio
2. Microwave
3. Visible light
4. Infrared

Q.

According to Maxwell, a changing electric field produces

1. Emf

2. Electric Current

3. Magnetic Field

4. Radiation pressure

Q.

What travels faster in a vacuum?

Q.

Can light travel forever?

Q.

Is radiation a wave or a particle?

Q. What causes reflection?

Q.

The range of frequencies allotted for FM radio is

1. $47$ to $230kHz$

2. $47$ to $230MHz$

3. $470$ to $960MHz$

4. $88$ to $108MHz$

Q. What is relativistic charged particle?

Q.

What is electromagnetism?

Q. Pick the type of radiation with the least wavelength range among the following.

1. Infrared
2. Ultraviolet
3. Microwave
4. Radio

Q.

The optical analogue of an equipotential surface is

Q.

If A and B are two points in the space, then how does light travel from point A to B?

1. 

2. 

3. 

4. 

Q.

Is transverse or longitudinal faster?

Q. Assertion :The basic difference between various types of electromagnetic waves lies in their wavelength or frequencies. Reason: Electromagnetic waves travel through vacuum with the same speed.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Which among the following coloured light has the shortest wavelength?

1. Blue

2. Red

3. Green

4. Yellow

Q.

What are the applications of microwaves?

Q.

Why does it hurt our eye when we look at the sun?

Q.

Out of the following options, which one can be used to produce a propagating electromagnetic wave?

1. A charge moving at constant velocity

2. A stationary charge

3. A chargeless particle

4. An accelerating charges

Q. Identify which of the following best describe the difference between electromagnetic (EM) waves and other types of waves?

1. EM waves can travel without a medium.
2. EM waves are higher in frequency than all other waves
3. EM waves have shorter wave lengths than any other type of wave.
4. EM waves transport matter and energy.
5. EM waves require a medium to travel.