How to solve the 16th question? current through a conductor in terms of 'drift veloc
OR
Describe briefly, with the help of a circuit diagram, how a potentiometer is used to determine the
internal resistance of a cell.
14. A convex lens of focal length fl is kept in contact with a concave lens of focal lengthf2. Find the focal
length Of the combination.
IS. In the block diagram ofa simple modulator for obtaining an AM signal, shown in the figure, identify
the boxes A and B. Write their functions.
AM
Wave
Modulating
signal
Carrier
16. In the circuit shown in the figure, identify the equivalent gate of the circuit and make its truth table.
17.
(a) For a given a.c., sin (Dt, show that the average power dissipated in a resistor R over
12
complete cycle is — im R
(b) A light bulb is rated at 100 W for a 220 V a.c. supply. Calculate the resistance of the bulb.
18. A rectangular conductor LMNO is placed in a uniform magnetic field of 0.5 T. The field is direct
perpendicular to the plane of the conductor. When the arm MN of length of 20 cm is moved towa
