Physics Past Questions

Which of the following media allow(s) the transmission of sound waves through them? I. Air II. Liquid III. Solid

Sixty complete waves pass a particular point in 4s. If the distance between three successive troughs of the waves is 15 m, calculate the speed of the waves.

A wire is stretched between two points, 1 m apart. If the speed of the wave generated on plucking the wire is 200 ms\(^{-1}\), what is the minimum frequency which will resonate with the wire?

An object is placed on the principal axis and at the centre of curvature of a concave mirror. The image of the object formed by the mirror is

Which of the following is not self-luminous?

The image of any real object formed by a diverging lens is always

Light travels in straight lines. In which of the following is this principle manifested? I. Pinhole camera II. Formation of shadows III. Diffraction of light IV. Occurrence of an eclipse.

A ray of light is incident on a body x as shown in the diagram above. What is the refractive index of the body?

A ray of light is incident on mirror m\(_1\) and after reflection is incident on mirror m\(_2\) as shown in the diagram above. Calculate the angle of reflection of the ray at mirror m\(_2\).

When two objects, P and Q, are supplied with the same quantity of heat, the temperature change in P is observed to be twice that in Q. If the masses of P and Q are the same, calculate the ratio of the specific heat capacities of Q to P.

How much heat is required to convert 20 g of ice at 0°C to water at the same temperature? [Specific latent heat of ice = 336 Jg\(^{-1}\)]

An iron rod of mass 2 kg and at a temperature of 280°C is dropped into some quantity of water initially at a temperature of 30°C. If the temperature of the mixture is 70°C, calculate the mass of the water. (Neglect heat losses to the surroundings) [Specific heat capacity of iron = 460 Jkg\(^{-1}\)K\(^{-1}\)] [Specific heat capacity of water = 4200 Jkg\(^{-1}\)K\(^{-1}\)]

The temperature of a glass vessel containing 100 cm\(^3\) of mercury is raised from 10°C to 100°C. Calculate the apparent cubic expansion of the mercury. (Real cubic expansivity of mercury = 1.8 × 10\(^{-4}\) K\(^{-1}\), Cubic expansivity of glass = 2.4 × 10\(^{-5}\) K\(^{-1}\))

The pressure of a given mass of gas changes from 200 Nm\(^{-2}\) to 100 Nm\(^{-2}\), while its temperature drops from 127°C to -73°C. Calculate the ratio of the final volume of the gas to its initial volume.

An air bubble of volume 2 cm\(^3\) is formed 20 m under water. What will be its volume when it rises to just below the surface of the water if the atmospheric pressure is equivalent to a height of 10 m of water?

Hot water at temperature of t is added to twice that amount of water at a temperature of 30°C. If the resulting temperature of the mixture is 50°C, calculate t

A body of specific heat capacity 450 Jkg\(^{-1}\)K\(^{-1}\) falls to the ground from rest through a vertical height of 20 m. Assuming conservation of energy, calculate the change in temperature of the body striking the ground level. (g = 10 ms\(^{-2}\))

A brass rod is 2 m long at a certain temperature. Calculate the linear expansion of the rod for a temperature change of 100 K. (Take linear expansivity of brass as 1.8 × 10\(^{-5}\) K\(^{-1}\))

A mercury-in-glass thermometer reads -20º at the ice point and 100º at the steam point. Calculate the Celsius temperature corresponding to 70º on the thermometer.