Archives

A charged particle oscillates about its mean equilibrium position with a frequency of 10⁹ Hz. The frequency of the electromagnetic wave produced by the oscillator is

1) 10 Hz 2) 105 Hz 3) 109 Hz 4) 1010 Hz Answer: 3) 109 Hz Solution: The frequency of the electromagnetic wave produced by the... View Article

The amplitude of the magnetic field part of a harmonic electromagnetic wave in a vacuum is B₀ = 510 nT. What is the amplitude of the electric field part of the wave?

1) 140 NC-1 2) 153 NC-1 3) 163 NC-1 4) 133 NC-1 Answer: 2) 153 NC-1 Solution: The magnitude of the electric field is E0 = B0c = 510... View Article

Radio waves of constant amplitude can be generated with

1) rectifier 2) filter 3) F.E.T 4) Oscillator Answer:4) Oscillator Solution: Radio waves are a type of electromagnetic radiation. The... View Article

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

1) Li02/2 2) B2/2μ0 3) μ0B2/2 4) μ0/2B2 Answer: 2) B2/2μ0 Solution: The energy density due to electric field =... View Article

The voltage applied across an X-rays tube is nearly equal to

1) 10 V 2) 100 V 3) 1000 V 4) 10,000 V. Answer: 4) 10,000 V. Solution: V = hc/eλ = (6.6 x 10-34 x 3 x 108)/(1.6 x 10-19 x... View Article

The wavelength of x-rays is of the order of

1) 1 metre 2) 1 cm 3) 1 micron 4) 1 angstrom Answer: 4) 1 angstrom Solution: The wavelength of x-rays is of the order of 1 angstrom... View Article

The equation out of four Maxwell’s equations which show electric field lines do not form closed loops

(i) (ii) (iii) (iv) 1) (i) only 2) (i) and (iv) when E is independent of time. 3) (iv) only when E is independent of time... View Article

Electromagnetic radiation has an energy of 13.2 keV. Then, the radiation belongs to the region of

1) visible light 2) ultraviolet 3) infrared 4) X – rays Answer: 4) X – rays Solution: Energy = 13.2 keV E = hν =... View Article

In an electromagnetic wave, the direction of propagation is in the direction of

1) E 2) B 3) E × B 4) None of these Answer: 3) E × B Solution: The direction of propagation of the electromagnetic wave is... View Article

Electromagnetic waves can be deflected by

1) electric field only 2) magnetic field only 3) Both (1) and (2) 4) None of the above Answer: 4) None of the above Electromagnetic waves... View Article

An electromagnetic wave of frequency v = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ε = 4.0. Then

1) wavelength is doubled and the frequency remains unchanged 2) wavelength is doubled and frequency becomes half 3) wavelength is halved and... View Article

The dielectric constant of air is 1.006. The speed of electromagnetic waves travelling in air is a × 10⁸ ms^-1, where, a is about

1) 3 2) 3.88 3) 2.5 4) 3.2 5) 2.8 Answer: 1) 3 Solution: Speed of electromagnetic wave, c = 1/√µ0ε0 = 3 x... View Article

A point source of electromagnetic radiation has an average power output of 1500 W. The maximum value of the electric field at a distance of 3 m from this source in Vm ^-1 is

1) 500 2) 100 3) 500/3 4) 250/3 5) 10√5 Answer: 2) 100 Solution: Average Intensity of an electromagnetic wave is Intensity, I=... View Article

An electromagnetic wave has

1) electric vector only 2) magnetic vector only 3) electric and magnetic vectors perpendicular to each other 4) Neither the electric vector... View Article

The speed of electromagnetic waves in a vacuum depends upon the source of radiation. It

1) increases as we move from γ-rays to radio waves 2) decreases as we move from γ-rays to radio waves 3) is the same for all of... View Article

During the propagation of electromagnetic waves in a medium,

1) electric energy density is double of the magnetic energy density 2) electric energy density is half of the magnetic energy density 3)... View Article

Which of the following shows the greenhouse effect?

1) Ultraviolet rays 2) Infrared rays 3) X – rays 4) None of these Answer: 2) Infrared rays Solution: Infrared rays are reflected... View Article

A rock of mass m is dropped to the ground from a height h. A second rock with a mass of 2m is dropped from the same height. When the second rock strikes the ground, what is its kinetic energy?

1) twice that of the first rock 2) four times that of the first rock 3) the same as that of the first rock 4) half that of the first rock... View Article

28 Oct 2021: PIB Summary & Analysis

TABLE OF CONTENTS 1. ICGS Ship Sarthak 2. India and ADB 3. Govt releases ₹40k crore to states, UTs as GST shortfall 4. National Formulary of... View Article

M	T	W	T	F	S	S
				1	2	3
4	5	6	7	8	9	10
11	12	13	14	15	16	17
18	19	20	21	22	23	24
25	26	27	28	29	30	31