Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Substances which have identical chemical properties but differ in atomic weight are called.

The value of stopping potential in the following diagram

(a) – 4V

(b) – 3 V

(c) – 2V

(d) – 1 V

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

Two parallel circular coils of equal radii having equal number of turns placed coaxially and separated by a distance equal to the radii of the coils carrying equal currents in same direction are known as:

Inside a conductor electrostatic field is:

A particle A has charge +q and a particle B has charge +4q with each of them having the same mass m. When allowed to fall from rest through the same electric potential difference, the ratio of their speed   will become

(a) 2 : 1

(b) 1 : 2

(c) 1 : 4

(d) 4 : 1

A particle of charge +q and mass m moving under the influence of a uniform electric field   and a uniform magnetic field   follows trajectory from P to Q as shown in figure. The velocities at P and Q are v  and -2v  respectively. Which of the following statement(s) is/are correct

(a) E =

(b) Rate of work done by electric field at P is

(c) Rate of work done by both the fields at Q is zero

(d) a, b, c

The rate of change of current needed to induce an emf of 8V in 0.1H coil is.

Assertion :   Photosensitivity of a metal is high if its work function is small.

Reason     : Work function =   where   is the threshold frequency.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

Which radiation in sunlight, causes heating effect

(a) Ultraviolet

(b) Infrared

(c) Visible light

(d) All of these