Advertisements
Advertisements
Question
Give two uses of Microwaves.
Solution
- In radar system for aircraft navigation
- Microwave oven for cooking
APPEARS IN
RELATED QUESTIONS
How are electromagnetic waves produced?
Write mathematical expressions for electric and magnetic fields of an electromagnetic wave propagating along the z-axis.
Suppose that the electric field amplitude of an electromagnetic wave is E0 = 120 N/C and that its frequency is v = 50.0 MHz.
- Determine B0, ω, k, and λ.
- Find expressions for E and B.
In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of 2.0 × 1010 Hz and amplitude 48 V m−1.
- What is the wavelength of the wave?
- What is the amplitude of the oscillating magnetic field?
- Show that the average energy density of the E field equals the average energy density of the B field.
[c = 3 × 108 m s−1]
About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation
(a) at a distance of 1 m from the bulb?
(b) at a distance of 10 m?
Assume that the radiation is emitted isotropically and neglect reflection.
What are the directions of electric and magnetic field vectors relative to each other and relative to the direction of propagation of electromagnetic waves?
The energy contained in a small volume through which an electromagnetic wave is passing oscillates with
A point charge is moving along a straight line with a constant velocity v. Consider a small area A perpendicular to the motion of the charge. Calculate the displacement current through the area when its distance from the charge is x. The value of x is not large, so that the electric field at any instant is essentially given by Coulomb's law.
The energy levels of an atom of a certain element are shown in the given figure. Which one of the transitions A, B, C, D or E will result in the emission of photons of electromagnetic radiation of wavelength 618.75 nm? Support your answer with mathematical calculations.
The dimension of `1/(mu_0 ∈_0)` is
Which of the following electromagnetic radiations is used for viewing objects through fog ______.
Which one of them is used to produce a propagating electromagnetic wave?
What are electromagnetic waves?
The direction of propagation of an electromagnetic plane wave is ______.
Velocity of plane electromagnetic waves in vacuum equals ______.
An accelerate electron would produce.
Electromagnetic waves are produced by ______.
A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. The electromagnetic waves produced ______.
- will have frequency of 109 Hz.
- will have frequency of 2 × 109 Hz.
- will have a wavelength of 0.3 m.
- fall in the region of radiowaves.
The source of electromagnetic waves can be a charge ______.
- moving with a constant velocity.
- moving in a circular orbit.
- at rest.
- falling in an electric field.
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?
- Radiation pressure is `I/c` if the wave is totally absorbed.
- Radiation pressure is `I/c` if the wave is totally reflected.
- Radiation pressure is `(2I)/c` if the wave is totally reflected.
- Radiation pressure is in the range `I/c < p < (2I)/c` for real surfaces.
