HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Important Questions

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?

Calculate the value of λ_max for radiation from a body having a surface temperature of 3000 K. (b = 2.897 x 10-3 m K) 

Draw a neat labeled diagram of Ferry’s black body. 

A metal cube of length 4 cm radiates heat at the rate of 10 J/s. Find its emissive power at a given temperature. 

Calculate the ratio of two specific heats of polyatomic gas molecules.  

The velocity of the three molecules is 2 km s^-1, 4 km s^-1, 6 km s^-1. Find (i) mean square velocity (ii) root mean square velocity. 

Derive Mayer’s relation.

The root mean square speed of the molecules of a gas is proportional to ______.
[T =Absolute temperature of gas]

The difference between the two molar specific heats of gas is 9000 J/kg K. If the ratio of the two specific heats is 1.5, calculate the two molar specific heats.

Compare the rate of loss of heat from a metal sphere at 827°C with the rate of loss of heat from the same at 427°C, if the temperature of the surrounding is 27°C.

State and prove the theorem of the parallel axis about the moment of inertia.

Show that the average energy per molecule is directly proportional to the absolute temperature ‘T’ of the gas.

Draw a neat labelled diagram of Ferry’s perfectly black body.

Compare the rms speed of hydrogen molecules at 227°C with the rms speed of oxygen molecules at 127°C. Given that molecular masses of hydrogen and oxygen are 2 and 32 respectively.

Prove the Mayer's relation `C_p - C _v = R/J`

A particle performing linear S.H.M. has a period of 6.28 seconds and a pathlength of 20 cm. What is the velocity when its displacement is 6 cm from mean position?

Define linear S.H.M.

If the metal bob of a simple pendulum is replaced by a wooden bob of the same size, then its time period will.....................

1. increase
2. remain same
3. decrease
4. first increase and then decrease.

A particle in S.H.M. has a period of 2 seconds and amplitude of 10 cm. Calculate the acceleration when it is at 4 cm from its positive extreme position.

Calculate the average molecular kinetic energy :

(a) per kilomole, (b) per kilogram, of oxygen at 27°C.

(R = 8320 J/k mole K, Avogadro's number = 6*03 x 10²⁶ molecules/K mole)