41.

Find the minimum wavelength of the emitted X-rays, when an X-ray tube is operated at 50 kV.

i) Define half-life of a radioactive substance.

ii) Using the equation, N = N_o e^-t, obtain the relation between half-life (T) and decay constant ( of a radioactive substance.

With the help of a suitable example and an equation, explain the term pair production.

Draw a labelled diagram of a full wave rectifier. Show how output voltage varies with time, if input voltage is a sinusoidal voltage.

What is a NAND gate? Write it's truth table?

Derive an expression for intensity of electric field at a point in broadside position or on an equatorial line of an electric dipole.

Figure below shows a capacitor C, an inductor L and resistor R, connected in series to an ac supply of 220 V.


Calculate:

i) the resonant frequency of the given LCR circuit

ii) current flowing through the circuit

iii) Average power consumed by the circuit.

On the basis of Huygen's wave theory of light, show that the angle of reflection is equal to the angle of incidence. You must draw a labelled diagram for this deviation.