NEET Physics Thermal Properties Of Matter MCQs

A platinum resistance thermometer has a resistance of $20 \Omega$ at $0^\circ C$ and $25 \Omega$ at $100^\circ C$. If its resistance is measured to be $24 \Omega$ when placed in a hot bath, what is the temperature of the bath, assuming a linear relationship between resistance and temperature?

A constant volume gas thermometer shows pressure readings of $P_1$ at the triple point of water and $P_2$ at the boiling point of water at 1 atm. What is the ideal gas temperature corresponding to a pressure reading of $2P_1$?

A thermocouple using iron and copper produces an emf of $E_1$ when its junctions are kept at $0^\circ C$ and $100^\circ C$. If the cold junction is kept at $-20^\circ C$ and the emf is $E_2$, what is the temperature of the hot junction?

A pyrometer is calibrated to measure temperatures in the range of 500°C to 2500°C. Which of the following is NOT a valid reason for choosing a pyrometer over a thermocouple in this temperature range?

Which of the following properties of materials is NOT utilized in temperature measurement devices?

A bimetallic strip made of materials X and Y, with linear expansion coefficients $\alpha_X$ and $\alpha_Y$ respectively ($\alpha_X > \alpha_Y$), is fixed at one end. When heated, the strip bends. A small mass 'm' is attached to the free end, producing a bending moment 'M'. If the temperature is further increased by $\Delta T$, and assuming the bending remains elastic, the additional bending moment required to keep the strip straight is:

A solid sphere of radius 'R' made of a material with a volume expansion coefficient '$\gamma$' is heated by $\Delta T$. The fractional change in its moment of inertia about a diameter is:

Two rods of identical dimensions but different materials, having linear expansion coefficients $\alpha_1$ and $\alpha_2$ ($\alpha_1 > \alpha_2$), are fixed at their ends and subjected to the same temperature increase. If the thermal stress developed in the rods are $\sigma_1$ and $\sigma_2$ respectively, which of the following is correct?

A pendulum clock keeps correct time at $20^\circ C$. The pendulum is made of a material with a linear expansion coefficient $\alpha$. If the temperature increases to $30^\circ C$, how much time will the clock gain or lose in one day?

A metal rod of length 'L' is clamped rigidly at its midpoint. If its temperature is increased by $\Delta T$, the longitudinal strain developed in the rod is: