Find the equivalent capacitance across $A$ and $B$ in $\mu F$.

Which of the following is $NOT$ a characteristic of chemisorption?

$A$ capacitor of capacity $4 \mu F$ is charged to $80 \ V$ and another capacitor of capacity $6 \mu F$ is charged to $30 \ V$. When they are connected,the energy lost by the $4 \mu F$ capacitor is: (in $mJ$)

$A$ projectile is fired at an angle of $45^\circ$ with the horizontal. The elevation angle of the projectile at its highest point as seen from the point of projection is:

The horizontal range is four times the maximum height attained by a projectile. The angle of projection is ......... $^o$

If $\frac{x^2}{a} + \frac{2xy}{h} + \frac{y^2}{b} = 0$ represents a pair of straight lines such that the slope of one of the lines is twice the other,then $\frac{ab}{h^2} =$