How does the effective power radiated by an antenna vary with wavelength?

List the effects of radiations.

How does the magnification (m) of the real image formed by a lens vary with the distance (x) of the object from the focus of a concave mirror ?

How does the intensity of a paramagnetic material vary with temperature?

How does the width of dark fringe in interference pattern vary from that of the bright fringe ?

Photocurrent recorded in the micro ammeter in an experimental set-up of photoelectric effect vanishes when the retarding potential is more than 0.8 V if the wavelength of incident radiation is 4950overset@ A . If the source of incident radiation is changed, the stopping potential turns out to be 1.2 V. Find the work function of the cathode material and the wavelength of the second source.

Photocurrent recorded in the micro ammeter in an experimental set-up of photoelectric effect vanishes when the retarding potential is more than 0.8 V if the wavelength of incident radiation is 4950 overset (@)(A) . If the source of incident radiation is changed, the stopping potential turns out to be 1.2 V. Find the work function of the cathode material and the wavelength of the second source .

Two bodies A and B having same surface areas have emmissivities of 0.01 and 0.49 respectively. The two bodies emit total radiant power at the same rate. The wavelength A8 corresponding to maximum spectral radiancy 111 the radiation from B shifted from the wavelength corresponding to maximum spectral radiancy in the radiation from A by 1 µm. Jf temperature of A is 5200 K then,

Assuming that the temperature at the surface of the Sun is 6000 K, find out the size of a virtual star (in terms of the size of Sun) whose surface temperature is 3000 K and the power radiated by the virtual star is 25 times the power radiated by the Sun. Treat both, the Sun and virtual star as a blackbody.