Which among the following is a benzylic halide?

Four smooth steel balls of equal mass at rest are free to move along a straight line without friction. The first ball is given a velocity of $0.4 \, m/s$. It collides head-on with the second elastically,the second one similarly with the third,and so on. The velocity of the last ball is .......... $m/s$.

If the polar of a point on the circle $x^2+y^2=p^2$ with respect to the circle $x^2+y^2=q^2$ touches the circle $x^2+y^2=r^2$,then $p, q, r$ are in

If $X$ is a Poisson variate such that $\alpha = P(X=1) = P(X=2)$,then $P(X=4)$ is equal to

Which of the following is a hydride?

In the Victor-Meyer's test,the colours given by $1^o$,$2^o$ and $3^o$ alcohols are respectively: