Two bulbs,one of $50\, W$ and another of $25\, W$,are connected in series to the mains. The ratio of the currents through them is:

Find the equivalent resistance between points $A$ and $B$.

Three voltmeters $A$,$B$ and $C$ having resistances $R$,$1.5 R$ and $3 R$ respectively are used in a circuit as shown. When a potential difference is applied between $X$ and $Y$,the readings of the voltmeters are $V_{1}$,$V_{2}$,and $V_{3}$ respectively. Then

The current $I$ flowing through the given circuit will be $.....A$.

When two resistors of $R \ \Omega$ value are connected in parallel,what is the equivalent resistance?

Two conductors have the same resistance at $0\,^{\circ}C$ but their temperature coefficients of resistance are $\alpha_1$ and $\alpha_2$. The respective temperature coefficients of their series and parallel combinations are nearly