WB JEE 2023 | Rotational Motion Question 5 | Physics

WB JEE 2023

MCQ (Single Correct Answer)

-0.25

A mouse of mass m jumps on the outside edge of a rotating ceiling fan of moment of inertia I and radius R. The fractional loss of angular velocity of the fan as a result is,

$$\frac{m R^{2}}{I+m R^{2}}$$

$$\frac{I}{I+m R^{2}}$$

$$\frac{I-m R^{2}}{I}$$

$$\frac{I-m R^{2}}{I+m R^{2}}$$

WB JEE 2021

MCQ (Single Correct Answer)

-0.5

A uniform rod of length L pivoted at one end P is freely rotated in a horizontal plane with an angular velocity $$\omega$$ about a vertical axis passing through P. If the temperature of the system is increased by $$\Delta$$T, angular velocity becomes $${\omega \over 2}$$. If coefficient of linear expansion of the rod is $$\alpha$$($$\alpha$$ << 1), then $$\Delta$$T will be

$${1 \over \alpha }$$

$${1 \over 2\alpha }$$

$${1 \over 4\alpha }$$

$$\alpha$$

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