$1\, g$ of hydrogen is converted into $0.993\, g$ of helium in a thermonuclear reaction. The energy released is

Which of the following is a hydride?

$A$ transistor is connected in common emitter $(CE)$ configuration. The collector supply is $8 \ V$ and the voltage drop across a resistor of $800 \ \Omega$ in the collector circuit is $0.5 \ V$. If the current gain factor $\alpha$ is $0.96$,find the base current in $\mu A$.

The modulus and amplitude of $\frac{1 + 2i}{1 - (1 - i)^2}$ are

If the direction cosines of two lines are given by $l+m+n=0$ and $l^2-5m^2+n^2=0$,then the angle between them is

The angle of elevation of an object from a point $P$ on the level ground is $\alpha$. Moving $d$ metres on the ground towards the object,the angle of elevation is found to be $\beta$. Then the height (in metres) of the object is