Electromagnetic Waves

If the acceleration due to gravity experienced by a point mass at a height h above the surface of earth is same as that of the acceleration due to gravity at a dept ah(h <e) from the earth surface. The value of a will be_______.

Match List – I with List – II:

List – I List – II

(A) UV rays (i) Diagnostic tool in medicine

(B) X-rays(ii) Water purification

(C) Microwave(iii) Communication, Radar

(D) Infrared wave(iv) Improving visibility in foggy daya

Choose the correct answer from the options given below:

The electric field of a plane electromagnetic wave is given by $\stackrel{?}{E}=E_0(\hat{x}+\hat{y})\mathrm{s}\mathrm{i}\mathrm{n}?(kz-\omega t)$  Its magnetic field will be given by:

Given below are two statements:

Statement I : A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves.

Statement II : In a material medium, the EM wave travels with speed v = $\frac{1}{\sqrt[]{{\mu }_0{\in }_0}}.$  In the light of the above statements, choose the correct answer for the options given below

An EM wave of intensity I falls on a surface kept in vacuum and exerts radiation pressure p on it. Which of the following are true?

(a) Radiation pressure is I/c if the wave is totally absorbed

(b) Radiation pressure is —I/c if the wave is totally reflected

(c) Radiation pressure is 2I/c if the wave is totally reflected

(d) Radiation pressure is in the range I/c < p < 2I/c for real surfaces

The source of electromagnetic waves can be a charge

(a) Moving with a constant velocity

(b) Moving in a circular orbit

(c) At rest

(d) Falling in an electric field

A charged particle oscillates about its mean equilibrium position with a frequency of 10⁹ The electromagnetic waves produced

(a) Will have frequency of 10⁹Hz

(b) Will have frequency of 2 x 10⁹ Hz

(c) Will have wavelength of 0.3 m

(d) Fall in the region of radio waves

A plane electromagnetic wave propagating along x-direction can have the following pairs of E and B.

(a) E_x, B_y       

(b) E_y, B_z

(c) B_x,E_y       

(d) E_z,B_y

An electromagnetic wave travelling along z-axis is given as E=E₀cos(kz-wt).choose the correct options from the following

(a) Tha associated magnetic field is given as B=1/ck $*$ E=1/w(k $*\mathit{E}$ )

(b) The electromagnetic field can be written in terms of associated magnetic field as E=c(b $*\mathit{k}$ )

(c) E=0,k.B=0

(d) K $*$ E=0,k $*\mathit{B}=0$

An electromagnetic wave travels in vacuum along z-direction E=  (E₁iE₂j)cos(kz-wt). Choose the correct options from the following

(a) The associated magnetic field is given as B= (E₁i-E₂j)cos(kz-wt)

(b) The associated magnetic field is given as B= (E₁i-E₂j)cos(kz-wt)

(c) The given electro magnetic field is circularly polarised

(d) The given electromagnetic wave is plane polarised