Physics MCQs for NEET — Practice Questions with Answers

$ Resistivity = { Resistance \times Area \over length} $

$ latent heat(Q)= { heat energy \over mass } $

Latent heat is the amount of heat required to change the state of a unit mass of a substance without changing its temperature. The dimensional formula for latent heat can be derived from the formula: \[ Q = m imes L \] where \( Q \) is the heat energy (\( M^1 L^2 T^{-2} \)), \( m \) is the mass (\( M^1 \)), and \( L \) is the latent heat. Solving for \( L \): \[ L = \frac{Q}{m} = \frac{M^1 L^2 T^{-2}}{M^1} = M^0 L^2 T^{-2} \] Thus, the correct dimensional formula for latent heat is \( M^0 L^2 T^{-2} \).

$ coefficient of viscosity = { Force \times time \over (length)^2 } $

Torque is the rotational equivalent of force and is given by the product of force and the perpendicular distance from the axis of rotation. The dimensional formula for torque can be derived from the formula: \[ au = F imes r \] where \( au \) is the torque, \( F \) is the force (\( M^1 L^1 T^{-2} \)), and \( r \) is the distance (\( L^1 \)). Solving for \( au \): \[ au = M^1 L^1 T^{-2} imes L^1 = M^1 L^2 T^{-2} \] Thus, the correct dimensional formula for torque is \( M^1 L^2 T^{-2} \).

The Boltzmann constant has the dimension is. energy/temperature.

The same as entropy.

so, the dimensional for

Boltzmann’s constant is  ML²T⁻²θ⁻¹

The product of capacitance (C) and resistance (R) yields a dimensional formula for time. Capacitance has the dimensional formula $[C] = M^{-1}L^{-2}T^4A^2$, and resistance has the dimensional formula $[R] = ML^2T^{-3}A^{-2}$. Multiplying these gives $[CR] = (M^{-1}L^{-2}T^4A^2) (ML^2T^{-3}A^{-2}) = T$. Therefore, the physical quantity with the dimensional formula of $CR$ is time period.