Electric Charges and Fields — Physics STD 12 Science — Question

Correct mathematical form of Ampere's rule is:

An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be

(a)

(b)

(c)

(d)

A capacitor of 4μ F is connected as shown in the circuit (Fig.). The internal resistance of the battery is 0.5Ω. The amount of charge on the capacitor plates will be:

Two files lines can ____.

In an insulator, the energy gap between conduction band and valence band is about:

Vapour is injected at a uniform rate in a closed veseel which was initially evacuated. The pressure in the vessel:

1. Increaaes continuously.
2. Decreases continuously.
3. First increases and then decreases.
4. First increases and then becomes constant.

When a potential difference is applied across, the current passing through

(a) An insulator at 0 K  is zero

(b) A semiconductor at 0 K  is zero

(c) A P-N diode at 300 K  is finite, if it is reverse biased

(d) a, b, c

A wire has a resistance of 6 W. It is cut into two parts and both half values are connected in parallel. The new resistance is ....

(a) 12 W

(b) 1.5 W

(c) 3 W

(d) 6 W

Two balls are thrown simultaneously in air. The acceleration of the centre of mass of the two balls while in air:

1. Depends on the direction of the motion of the balls.
2. Depends on the masses of the two balls.
3. Depends on the speeds of the two balls.
4. Is equal to g.

A coil of area  has 500 turns. Magnetic field of   is perpendicular to the coil. The field is reduced to zero in 0.1 second. The induced e.m.f. in the coil is

(a) 1 V

(b) 5 V

(c) 50 V

(d)  Zero