Electric Charges and Fields — Physics STD 12 Science — Question

For a given temperature difference, which of the following pairs will generate maximum thermo e.m.f.

(a) Antimony-bismuth

(b) Silver-gold

(c) Iron-copper

(d) Lead-nickel

Electroscope is used:

The distance between the ends of the wings of an airplane is 50m. It is flying in a horizontal plane at a speed of 360Km/ hour. The vertical component of earth's magnetic field at that place is 2.0 × 10^-4Wb/ m², then the potential difference induced between the ends of the wings will be

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

For germanium crystal, the forbidden energy gap in joules is

(a) 1.12

(b) 1.76

(c)  1.6

(d) Zero

Which of the following quantities is the same for all ideal gases at the same temperature?

1. The kinetic energy of 1 mole.
2. The kinetic energy of 1g.
3. The number of molecules in 1 mole.
4. The number of molecules in 1g.

The electron emitted in beta radiation originates from

(a) Inner orbits of atoms	(b) Free electrons existing in nuclei
(c) Decay of a neutron in a nucleus	(d) Photon escaping from the nucleus

How does the potential difference change with the effect of the dielectric when the battery remains connected across the capacitor?

The binding energies per nucleon for a deuteron and an α- particle are x₁ and x₂ respectively. What will be the energy Q released in the reaction  

(a) 4

(b) 4

(c) 2(

(d) 2