HSC Science (Computer Science) १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions for Physics

Explain, on the basis of the kinetic theory of gases, how the pressure of a gas changes if its volume is reduced at a constant temperature.

Calculate the ratio of the mean square speeds of molecules of a gas at 30 K and 120 K.

Two vessels A and B are filled with the same gas where the volume, temperature, and pressure in vessel A is twice the volume, temperature, and pressure in vessel B. Calculate the ratio of the number of molecules of the gas in vessel A to that in vessel B.

Find the kinetic energy of 5 litres of a gas at STP, given the standard pressure is 1.013 × 10⁵ N/m².

Calculate the average molecular kinetic energy 

1. per kmol 
2. per kg 
3. per molecule 

of oxygen at 127°C, given that the molecular weight of oxygen is 32, R is 8.31 J mol⁻¹K⁻¹ and Avogadro’s number N_A is 6.02 × 10²³ molecules mol⁻¹.

Energy is emitted from a hole in an electric furnace at the rate of 20 W when the temperature of the furnace is 727°C. What is the area of the hole? (Take Stefan’s constant σ to be 5.7 × 10^-8 Js^-1 m^-2K^-4.)

The emissive power of a sphere of area 0.02 m² is 0.5 kcal s^-1m^-2. What is the amount of heat radiated by the spherical surface in 20 seconds?

Compare the rates of emission of heat by a blackbody maintained at 727°C and at 227°C, if the black bodies are surrounded by an enclosure (black) at 27°C. What would be the ratio of their rates of loss of heat?

Earth’s mean temperature can be assumed to be 280 K. How will the curve of blackbody radiation look like for this temperature? Find out λ_max. In which part of the electromagnetic spectrum, does this value lie? (Take Wien's constant b = 2.897 × 10⁻³ m K)

Find the temperature of a blackbody if its spectrum has a peak at (a) λ_max = 700 nm (visible), (b) λ_max = 3 cm (microwave region) (c) λ_max = 3 m (short radio waves). (Take Wien’s constant b = 2.897 × 10^-3 m.K).

An ideal monoatomic gas is adiabatically compressed so that its final temperature is twice its initial temperature. What is the ratio of the final pressure to its initial pressure?

Answer in brief.

Using differential equations of linear S.H.M, obtain the expression for (a) velocity in S.H.M., (b) acceleration in S.H.M.

Find the change in length of a second’s pendulum, if the acceleration due to gravity at the place changes from 9.75 m/s² to 9.8 m/s².

Answer in brief.

For a stationary wave set up in a string having both ends fixed, what is the ratio of the fundamental frequency to the second harmonic?

Derive an expression for the equation of stationary wave on a stretched string.

Find the amplitude of the resultant wave produced due to interference of two waves given as y₁ = A₁ sinωt, y₂ = A₂ sin(ωt + φ)

Describe how a potentiometer is used to compare the emf's of two cells by the combination method.

Why is a potentiometer preferred over a voltmeter for measuring emf?

A standing wave is produced in a tube open at both ends. The fundamental frequency is 300 Hz. What is the length of the tube? (speed of the sound = 340 m s^-1).

The resistance of a potentiometer wire is 8 Ω and its length is 8 m. A resistance box and a 2 V battery are connected in series with iL What should be the resistance in the box if it is desired to have a potential drop of 1 µV/mm?