The major product of the following reaction is

The work done by a force $\vec F = (-6x^3 \hat i) \, N$,in displacing a particle from $x = 4 \, m$ to $x = -2 \, m$ is ................ $J$.

$A$ solid sphere of mass $m$ rolls without slipping with velocity $v$ and compresses a spring of spring constant $k$ as shown in the figure. The maximum compression in the spring will be:

Two plane mirrors $A$ and $B$ are placed parallel to each other as shown in the figure. $A$ light ray is incident at an angle of $30^{\circ}$ at a point on mirror $A$. The plane of incidence coincides with the plane of the figure. What is the maximum number of reflections (including the first one) the ray will undergo before it emerges?

In a transistor,the collector current is always less than the emitter current because:

The major product of the following reaction is