In the reaction $LiH + AlH_3 \rightarrow LiAlH_4$,$AlH_3$ and $LiH$ act as:

If $A$ is a $3 \times 4$ matrix and $B$ is a matrix such that $A'B$ and $BA'$ are both defined,then $B$ is of the type:

$A$ particle moves along the curve $y=x^2+2x$. The point on the curve such that the $x$ and $y$ coordinates of the particle change at the same rate is

There are two coils $A$ and $B$ as shown in the figure. No current flows in $B$ if $A$ is at rest. Now,the coil $A$ is made to rotate about a vertical axis. At the shown instant $(t = 0)$,what will be the direction of the current in coil $A$ if the induced current in coil $B$ is counterclockwise?

$A$ disc has mass $m$ and radius $R$. How much tangential force should be applied to the rim of the disc so as to rotate it with angular velocity $\omega$ in time $t$?

In a $\triangle ABC$,$\cos \left(\frac{B+2C+3A}{2}\right) + \cos \left(\frac{A-B}{2}\right)$ is equal to