Two rods of same length and material are joined end to end. They transfer heat in 8 second. When they are joined in parallel they transfer same amount of heat in same conditions in time

The molar specific heats of an ideal gas at constant pressure and volume are denoted by '$$\mathrm{C}_{\mathrm{p}}$$' and '$$C_v$$' respectively. If $$\gamma=\frac{C_p}{C_v}$$ and '$$R$$' is universal gas constant, then $$C_v$$ is equal to

The temperature difference bewtween two sides of metal plate, $$3 \mathrm{~cm}$$ thick is $$15^{\circ} \mathrm{C}$$. Heat is transmitted through plate at the rate of $$900 \mathrm{~kcal}$$ per minute per $$\mathrm{m}^2$$ at steady state. The thermal conductivity of metal is

A black body has maximum wavelength '$$\lambda_{\mathrm{m}}$$' at temperature $$2000 \mathrm{~K}$$. Its corresponding wavelength at temperature $$3000 \mathrm{~K}$$ will be