The cell reaction $Mn + 2Ag_{(C_1)}^{+} (aq) \to Mn_{(C_2)}^{+2} (aq) + 2Ag$ is represented by

The Cartesian form of the polar equation $\theta = \tan^{-1} 2$ is

$Assertion (A)$: van der Waals' forces are responsible for chemisorption. $Reason (R)$: High temperature is favourable for chemisorption. The correct answer is

Which of the following is a biodegradable polymer?

The pulley and spring are massless,and friction is absent everywhere. The $5\,kg$ block is released from rest. The speed of the $5\,kg$ block when the $2\,kg$ block leaves contact with the ground is (take the force constant of the spring $K = 40\,N/m$ and $g = 10\,m/s^2$):

$A$ ball of mass $M$ falls from a height $h$ on a floor for which the coefficient of restitution is $e$. The height attained by the ball after two rebounds is