Gravitation — Physics STD 11 Science — Question

Find the surface energy of water kept in a cylindrical vessel of radius 6.0cm. Surface tension of water = 0.075J/m².

A stone of mass 0.25 kg tied to the end of a string is whirled round in a circle of radius 1.5 m with a speed of 40 rev./min in a horizontal plane. If the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks :
(a) the stone moves radially outwards.
(b) the stone flies off tangentially from the instant the string breaks.
(c) the stone flies off at an angle with the tangent whose magnitude depends on the speed of the particle?

Is it possible to heat a body without providing heat energy? How?

The lower end of a capillary tube of radius 1mm is dipped vertically into mercury:

1. Find the depression of mercury column in the capillary.
2. If the length dipped inside is half the answer of part (a), find the angle made by the mercury surface at the end of the capillary with the vertical. Surface tension of mercury = 0.465N/m and the contact angle of mercury with glass = 135^°.

Name the waves which do not require any material medium for their propagation.

What is the minimum possible temperature on the basis of Charles' law?

An AC source is connected to a capacitor. Will the rms current increase, decrease or remain constant if a dielectric slab is inserted into the capacitor?

Choose the correct alternative :
(a) If the zero of potential energy is as infinity, the total energy of an orbiting satellite is negative of its kinetic/potential energy.
(b) The energy required to launch an orbiting satellite out of earth's gravitational influence is more/ less than the energy required to project a stationary object at the same height (as the satellite) out of earth's influence.

What are the dimensions of a and b in the relation: F = a + bx , where F is force and (x) is distance?