$A$ battery is used to charge a parallel plate capacitor until the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor to the work done by the battery is

Which of the following substances has the highest melting point?

Hydrolysis of $NCl_3$ gives $NH_3$ and $X$. Which of the following is $X$?

$A$ particle performs linear $SHM$. At a particular instant,the velocity of the particle is $u$ and acceleration is $\alpha$ (both having the same direction). At another instant,the velocity is $v$ and acceleration is $\beta$ $(0 < \alpha < \beta)$ (both in opposite directions to each other). The distance between the two positions is

Six identical conducting rods are joined as shown in the figure. Points $A$ and $D$ are maintained at temperatures $200\,^{\circ}C$ and $20\,^{\circ}C$,respectively. The temperature of junction $B$ will be ......... $^{\circ}C$.

If $\frac{1}{x(x + 1)(x + 2).....(x + n)} = \frac{A_0}{x} + \frac{A_1}{x + 1} + \frac{A_2}{x + 2} + ..... + \frac{A_n}{x + n}$,then $A_r = $