JEE PYQ: Laws Of Motion Question 24
Question 24 - 2019 | 10 Apr Shift 2] (MCQ)
Light is incident normally on a completely absorbing surface with an energy flux of $25,\text{Wcm}^{-2}$. If the surface has an area of $25,\text{cm}^2$, the momentum transferred to the surface in 40 min time duration will be :
(1) $6.3 \times 10^{-4}$ Ns
(2) $1.4 \times 10^{-6}$ Ns
(3) $5.0 \times 10^{-3}$ Ns [Correct]
(4) $3.5 \times 10^{-6}$ Ns
Show Answer
Answer: (3)
Solution
Momentum $= \frac{IA \cdot t}{c} = \frac{25 \times 25 \times 10^{-4} \times 2400}{3 \times 10^8} = 5 \times 10^{-3}$ Ns.
BETA
