Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A 5.0 amp current is setup in an external circuit by a 6.0 volt storage battery for 6.0 minutes. The chemical energy of the battery is reduced by

(a) 1.08 × 104 J

(b) 1.08 × 10-4 volt

(c) 1.8 × 104 J

(d) 1.8 × 104 volt

The work function of a metallic surface is 5.01 eV. The photo-electrons are emitted when light of wavelength 2000Å falls on it. The potential difference applied to stop the fastest photo-electrons is  [h = 4.14

(a) 1.2 volts

(b) 2.24 volts

(c) 3.6 volts

(d) 4.8 volts

The rate of disintegration was observed to be  disintegrations per sec when its half life period is 1445 years. The original number of particles are

(a) 8.9

(b) 6.6

(c) 1.4

(d) 1.2

What is the electric potential at the perpendicular bisector of an electric dipole?

In a npn transistor circuit, the collector current is 10mA. If 95 per cent of the electrons emitted reach the collector, which of the following statements are true?

A parallel plate condenser is immersed in an oil of dielectric constant 2. The field between the plates is:

The high temperature required to initiate the nuclear fusion reaction is to overcome the _______ present between the atoms.

Two long parallel wires are at a distance 2d apart. They carry steady equal currents flowing out of the plane of the paper, as shown. The variation of the magnetic field B along the line XX’ is given by

(a)

(b)

(c)

(d)

Energy required to remove an electron from aluminium surface is 4.2 eV. If light of wavelength 2000 Å falls on the surface, the velocity of the fastest electron ejected from the surface will be

(a) 8.4

(b) 7.4

(c) 6.4

(d) 8.4