Wave Optics — Physics STD 12 Science — Question

Two spheres A and B of radius 4cm and 6cm are given charges of 80 μC and 40 μC respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is (a) 20 μC from A to B  (b) 16 μC from A to B (c) 32 μC from B  to A (d) 32 μC from A to B

An object may have:

1. Varying speed without having varying velocity.
2. Varying velocity without having varying speed.
3. Nonzero acceleration without having varying velocity.
4. Nonzero acceleration without having varying speed.

Mark the correct options:

1. If the far point goes ahead, the power of the divergent lens should be reduced.
2. If the near point goes ahead, the power of the convergent lens should be reduced.
3. If the far point is 1 m away from the eye, divergent lens should be used.
4. If the near point is 1 m away from the eye, divergent lens should be used.

Which of the following is not electromagnetic wave ?

Three capacitors of 2.0, 3.0  and  6.0 μF are connected in series to a  10 V  source. The charge on the 3.0 μF  capacitor is(a) 5 μC(b) 10 μC(c) 12 μC(d) 15 μC

The characteristic impedance of a coaxial cable is of the order of(a) 50 W  (b) 200 W(c) 270 W(d) None of these

Smaller pieces of heavy stones and metals which on entering earth's atmosphere burns out are (a) Comets(b) Meteorites(c) Asteroids(d) All of these

The truth table shown in figure is for (a) XOR(b) AND(c) XNOR(d) OR