Thermal Properties of Matter — NEET PYQ

The coefficient of linear expansion of brass is 19 × 10⁻⁶ /°C. If a brass rod is 1 m at 20°C, its length at 120°C is:

Two metal rods A (α₁) and B (α₂) of same length are heated equally. For equal expansion:

The SI unit of thermal conductivity is:

A black body at 727°C emits radiation at rate E. At 1727°C, the rate is:

Wien's displacement law relates:

The thermal resistance of a rod of length l, area A and conductivity K is:

Water has maximum density at:

The equivalent thermal conductivity of two slabs in series of equal area, lengths l₁ and l₂, conductivities K₁ and K₂ is:

Newton's law of cooling is valid when temperature difference between body and surroundings is:

A body cools from 80°C to 70°C in 5 min. Time to cool from 70°C to 60°C (surroundings at 20°C):

The rate of heat conduction through a slab does NOT depend on:

If the radius of a star becomes half and temperature doubles, its luminosity becomes:

Specific heat capacity of water is approximately:

The latent heat of fusion of ice is:

A copper rod and a steel rod of same dimensions are connected end to end. Free ends are at 100°C and 0°C. Temperature at junction (K_Cu = 400, K_St = 50 W/mK):

Two bodies at temperatures T₁ and T₂ (T₁ > T₂) are brought in contact. The final temperature is closer to:

The emissive power of a body at temperature T is E. The wavelength at which maximum emission occurs λ_m is proportional to:

The greenhouse effect is caused by gases that absorb:

A calorimeter of water equivalent 20 g contains 100 g water at 25°C. 50 g of water at 50°C is added. Final temperature:

Triple point of water is: