Question

The force exerted on $5\text{kg}$ block by $10\text{kg}$ block placed in the lift, shown in the figure is

Answer 1

FBD of $5\text{kg}$ block

$\therefore$ Force exerted on $5\text{kg}$ by $10\text{kg}$ block is $N_2$

Net force on $5\text{kg}$ block is zero w.r.t to lift frame.
$N_2-5g-15=0$
or $N_2=65N$

Hence, Option $\left(C\right)$ is the correct answer.