PUC Science कक्षा ११ - Karnataka Board PUC Question Bank Solutions for Physics

Is heat a conserved quantity?

A spinning wheel A is brought in contact with another wheel B, initially at rest. Because of the friction at contact, the second wheel also starts spinning. Which of the following energies of the wheel B increases?
(a) Kinetic
(b) Total
(c) Mechanical
(d) Internal

In a calorimeter, the heat given by the hot object is assumed to be equal to the heat taken by the cold object. Does it mean that heat of the two objects taken together remains constant?

A body A is placed on a railway platform and an identical body B in a moving train. Which of the following energies of B are greater than those of A, as seen from the ground?
(a) Kinetic
(b) Total
(c) Mechanical
(d) Internal

Consider a collision between an oxygen molecule and a hydrogen molecule in a mixture of oxygen and hydrogen kept at room temperature. Which of the following are possible?
(a) The kinetic energies of both the molecules increase.
(b) The kinetic energies of both the molecules decrease.
(c) kinetic energy of the oxygen molecule increases and that of the hydrogen molecule decreases.
(d) The kinetic energy of the hydrogen molecule increases and that of the oxygen molecule decreases.

As the temperature is increased, the time period of a pendulum

When a solid melts or a liquid boils, the temperature does not increase even when heat is supplied. Where does the energy go?

Consider a mixture of oxygen and hydrogen kept at room temperature. As compared to a hydrogen molecule an oxygen molecule hits the wall

A person's skin is more severely burnt when put in contact with 1 g of steam at 100°C than when put in contact with 1 g of water at 100°C. Explain

The atmospheric temperature in the cities on sea-coast change very little. Explain

Should a thermometer bulb have large heat capacity or small heat capacity?

Water equivalent of a body is measured in ___________ .

When a hot liquid is mixed with a cold liquid, the temperature of the mixture ____________ .

Which of the following pairs of physical quantities may be represented in the same unit?

Two bodies at different temperatures are mixed in a calorimeter. Which of the following quantities remains conserved?

The mechanical equivalent of heat ____________ .

The heat capacity of a body depends on

(a) the heat given

(b) the temperature raised

(c) the mass of the body

(d) the material of the body

If heat is supplied to a solid, its temperature

(a) must increase

(b) may increase

(c) may remain constant

(d) may decrease

The temperature of a solid object is observed to be constant during a period. In this period

(a) heat may have been supplied to the body

(b) heat may have been extracted from the body

(c) no heat is supplied to the body

(d) no heat is extracted from the body