An atomic power nuclear reactor can deliver $300\, MW$. The energy released due to fission of each nucleus of uranium atom $^{235}U$ is $170\, MeV$. The number of uranium atoms fissioned per hour will be

Which of the following equations is a balanced one?

Two identical balls $A$ and $B$ are released from the positions shown in the figure. They collide elastically on the horizontal portion $MN$. The ratio of the heights attained by $A$ and $B$ after the collision will be: (neglect friction)

$A$ $100 \ mL$ solution of $0.1 \ N$ $HCl$ was titrated with $0.2 \ N$ $NaOH$ solution. The titration was discontinued after adding $30 \ mL$ of $NaOH$ solution. The remaining titration was completed by adding $0.25 \ N$ $KOH$ solution. The volume of $KOH$ required for completing the titration is $............ \ mL$.

$A$ proton, a deuteron, and an $\alpha$-particle having the same momentum enter a region of uniform electric field between the parallel plates of a capacitor. The electric field is perpendicular to the initial path of the particles. The ratio of deflections suffered by them is

If the sum of two unit vectors is a unit vector,what is the magnitude of their difference?