Magnetism And Matter — Physics STD 12 Science — Question

If 2.2kW power is transmitted through a 100Ω  line at 22,000 V,  the power loss in the form of heat will be

(a) 0.1 W

(b) 1 W

(c) 10 W

(d) 100 W

At zero Kelvin a piece of germanium

(a) Becomes semiconductor	(b) Becomes good conductor
(c) Becomes bad conductor	(d) Has maximum conductivity

A silver voltameter of resistance 2 ohm and a 3 ohm resistor are connected in series across a cell. If a resistance of 2 ohm is connected in parallel with the voltameter, then the rate of deposition of silver

(a) Decreases by 25%	(b) Increases by 25%
(c) Increases by 37.5%	(d) Decreases by 37.5%

A perpendicular material is place in a magnetic fields. Consider the following statemetns:

1. If the magnetic field is increased, the magnetization is increased.
2. If the temperature is increased, the magnetization is increased.

1. Both A and B are true.
2. A is true but B is false.
3. B is true but A is false.
4. Both A and B are false.

Number of electrons in 1 Coulomb charge is _________?

Figure shows electric field lines in which an electric dipole p is placed as shown. Which of the following statements is correct?

The pressure p and volume V of an ideal gas both increase in a process.

1. Such a process is not possible.
2. The work done by the system is positive.
3. The temperature of the system must increase.
4. Heat supplied to the gas is equal to the change in internal energy.

What is the de-Broglie wavelength of the α - particle accelerated through a potential difference V

(a)  Å

(b) Å

(c) Å

(d) Å

Two conducting circular loops F and G are kept in a plane on either side of a straight current-carrying wire as shown in the figure below. If the current in the wire decreases in magnitude, the induced current in the loops will be.