Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A current carrying coil is placed with its axis perpendicular to N-S direction. Let horizontal component of earth's magnetic field be H_o and magnetic field inside the loop is H. If a magnet is suspended inside the loop, it makes angle θ with H. Then θ =

(a)

(b)

(c)

(d)

Let V and E represent the gravitational potential and field at a distance r from the centre of a uniform solid sphere. Consider the two statements:

1. The plot of V against r is discontinuous.
2. The plot of E against r is discontinuous.

1. Both A and B are correct.
2. A is correct but B is wrong.
3. B is correct but A is wrong.
4. Both A and B are wrong.

Alternating current is produced in:

Photoelectric effect was discovered by:

Circular part in the centre of retina is called

(a)  Blind spot

(b) Yellow spot

(c) Red spot

(d) None of the above

The frequency response curve of RC coupled amplifier is shown in figure. The band width of the amplifier will be

(a)

(b)

(c)

(d)

The wave-like character was experimentally proved for light by:

The polarisation of electromagnetic wave is in:

In the case of bar magnet, lines of magnetic induction

(a) Start from the north pole and end at the south pole

(b) Run continuously through the bar and outside

(c) Emerge in circular paths from the middle of the bar

(d) Are produced only at the north pole like rays of light from a bulb

The slope of plate characteristic of a vacuum tube diode for certain operating point on the curve is   The plate resistance of the diode and its nature respectively

(a) 100 kilo-ohms static	(b) 1000 kilo-ohms static
(c) 1000 kilo-ohms dynamic	(d) 100 kilo-ohms dynamic