A straight wire of resistance $18 \Omega$ is bent in the form of an equilateral triangular loop. The effective resistance between any two vertices of the triangle is

The power dissipated by a uniform wire of resistance $100 \Omega$ when a potential difference of 120 V is applied across its ends is

A wire of resistance $100 \Omega$ is stretched, so that its length increases by $20 \%$. The stretched wire is then bent in the form of a rectangle whose length and breadth are in the ratio $3: 2$. The effective resistance between the ends of any diagonal of the rectangle is

In a potentiometer experiment, when two cells of emfs $E_1$ and $E_2\left(E_2>E_1\right)$ are connected in series, the balancing length is 160 cm . If one of the cells is reversed, the balancing length decreases by $75 \%$. If $E_1=1.2 \mathrm{~V}$, then $E_2=$