An ideal coil of $10\,H$ is connected in series with a resistance of $5\,\Omega$ and a battery of $5\,V$. After $2\,s$ the connection is made,the current flowing in ampere in the circuit is

$A$ ping-pong ball of mass $m$ is floating in air by a jet of water emerging out of a nozzle. If the water strikes the ping-pong ball with a speed $v$ and just after collision the water falls dead,the mass flow rate of water in the nozzle is equal to

If the lines $\frac{x-1}{2}=\frac{y+1}{3}=\frac{z-1}{4}$ and $\frac{x-3}{1}=\frac{y-k}{2}=\frac{z}{1}$ intersect,then the value of $k$ is:

Which one of the following compounds gives aspirin on reacting with acetic anhydride in the presence of conc. $H_2SO_4$?

Which of the following combinations should be selected for better tuning of an $L-C-R$ circuit used for communication?

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