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प्रश्न
Give two uses of UV radiation.
उत्तर
- To destroy bacteria
- To burglar alarm.
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संबंधित प्रश्न
Write mathematical expressions for electric and magnetic fields of an electromagnetic wave propagating along the z-axis.
Write any two important properties of electromagnetic waves.
A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. What is the frequency of the electromagnetic waves produced by the oscillator?
A plane electromagnetic wave is travelling through a medium along the +ve z-direction. Depict the electromagnetic wave showing the directions of the oscillating electric and magnetic fields.
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.
Consider a parallel plate capacitor whose plates are closely spaced. Let R be the radius of the plates and the current in the wire connected to the plates is 5 A, calculate the displacement current through the surface passing between the plates by directly calculating the rate of change of flux of electric field through the surface.
For a plane electromagnetic wave propagating in x-direction, which one of the following combinations gives the correct possible directions for electric field (E) and magnetic field (B) respectively?
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.
Why is the orientation of the portable radio with respect to broadcasting station important?
What is the source of energy of electromagnetic waves?
