Question

Match the statements in Column with the results in Column and indicate your answer

| Column – I | Column – II |
| (a) A thin uniform spherical shell of surface area '' has an nitial temperature more than its surrounding atmosphere. Then magnitude of rate of change of its temperature with time (assuming density of material ** constant) | (P) is independent of '' |
| (b) A soap bubble initially in equilibrium is given a charge Q, which distributes uniformly over its surface. The centre of the bubble is always fixed. For the duration the bubble having surface area '' expands, the magnitude of electric potential at a fixed point always lying outside the bubble | (Q) depends on '' |
| (c) A container with open top and filled with ideal liquid is placed at rest on a smooth horizontal table. A small of area '' is drilled at the bottom of a side wall of container. The magnitude of force exerted by escaping liquid on the container | (R) **** constant |
| (d) An infinitely long straight current carrying wire ** along the axis of a closed cylindrical surface of total surface area '' in space. As the magnitude of current in the wire is continuously increased, the magnitude of the magnetic flux through the surface of this cylinder | ( *) decreases with time |

Answer 1

Correct option (a) P, (B) P,R (C) Q, (D) P,R

Explanation:

(a) The rate of change of heat energy of thin shell of mass m, specific heat C, radius R and width d R is given by

Hence the magnitude of rate of change of temperature

(B) The potential outside bubble can be found by simply concentrating net charge on bubble at its centre. Hence potential at fixed point outside is constant and independent of *.

(C) The magnitude of force exerted by liquid of density r escaping with speed v is rSv2. Hence this force depends on * and decreases with time as amount of liquid in container decreases resulting in continuous decrease of v.

(D) The magnitude flux through surface of closed cylinder is zero. Hence it is constant and independent of .