Two resistances $R_1$ and $R_2$ when connected in series and parallel with a $120\, V$ line,the power consumed is $25\, W$ and $100\, W$ respectively. The ratio of the power consumed by $R_1$ to that consumed by $R_2$ is:

The cold junction of a thermocouple is at $0^{\circ} C$. The thermo e.m.f. produced in the thermocouple is given by the equation $E = 16T - 0.04T^2$, where $T$ is the temperature of the hot junction. The temperature of inversion and the neutral temperature of the thermocouple are:

$A$ coil takes $15\,min$ to boil a certain amount of water,and another coil takes $20\,min$ for the same process. What is the time taken to boil the same amount of water when both coils are connected in series?

$A$ wire of $20 \Omega$ is immersed in ice. If $10 \ A$ current is passed through this wire for $1 \ minute$,the ice completely melts. The mass of the ice is nearly $(L_{\text{ice}} = 79.7 \ cal \ g^{-1})$

$A$ uniform metallic wire of length $L$ is mounted in two configurations. In configuration $1$ (triangle),it is an equilateral triangle and a voltage $V$ is applied to corners $A$ and $B$. In configuration $2$ (circle),it is bent in the form of a circle and the potential $V$ is applied at diametrically opposite points $P$ and $Q$. The ratio of the power dissipated in configuration $1$ to configuration $2$ is

The Peltier coefficient for the junction of a pair of metals is proportional to: