STD 11 - 6. system of particles and rotational motion — NEET STD 11 Science — Question

$\Rightarrow d L=\tau d t$

Taking torque about lowest point distance of force applied from lowest point $=(R+$$r)$

$\tau=2 t(R+r)$$...(1)$

$\Rightarrow d L=2 t(R+r) d t$

at after time t, the angular momentum becomes

$L=\int_{0}^{L} d L=\int_{0}^{t} 2 t(R+r)$

$\Rightarrow L=(R+r) t^{2}$