Magnetism And Matter — Physics STD 12 Science — Question

Which type of a physical quantity is electric current?

A piece of wood is taken deep inside a long column of water and released. It will move up:

1. With a constant upward acceleration.
2. With a decreasing upward acceleration.
3. With a deceleration.
4. With a uniform velocity.

A capacitor is charged by a battery and then the battery is disconnected. A dielectric slab is introduced between the plates. The result is:

When a current of 1 ampere is passed through a conductor whose ends are maintained at temperature difference of 1 ℃, the amount of heat evolved or absorbed is called

(a) Peltier coefficient	(b) Thomson coefficient
(c) Thermoelectic power	(d) Thermo e.m.f.

The relative atomic masses of many elements are not whole numbers because:

A 25 watt, 220 volt bulb and a 100 watt, 220 volt bulb are connected in parallel across a 220 volt line. Which bulb will glow more brightly

(a) 25 watt bulb	(b) 100 watt bulb
(c) Both will have same brightness	(d) First 25 watt then 100 watt

For sky wave propagation of a 10 MHz signal, what should be the minimum electron density in ionosphere

(a) ~ 1.2 × 1012 m–3

(b) ~ 106 m–3

(c) ~ 1014 m–3

(d) ~ 1022 m–3

Watt-hour meter measures

(a) Electric energy

(b) Current

(c) Voltage

(d) Power

Two electrolytic cells containing  and  respectively are connected in series and a current is passed through them until 1 mg of copper is deposited in the first cell. The amount of silver deposited in the second cell during this time is approximately [Atomic weights of copper and silver are respectively 63.57 and 107.88]

(a) 1.7 mg

(b) 3.4 mg

(c) 5.1 mg

(d) 6.8 mg