A galvanometer of resistance ' $G$ ' is shunted by resistance of 'S' ohm. To keep the main current in the circuit unchanged the resistance to be put in series with Galvanometer is

The resistances in the left and right gap of a metre bridge are $40 \Omega$ and $60 \Omega$ respectively. When the bridge is balanced, the distance of the null point from the centre of the wire towards left is

When moving coil galvanometer (MCG) is converted into a voltmeter, the series resistance is '$$n$$' times the resistance of galvanometer. How many times that of MCG the voltmeter is now capable of measuring voltage?

In potentiometer experiment, the balancing length is $$8 \mathrm{~m}$$ when two cells $$E_1$$ and $$E_2$$ are joined in series. When two cells are connected in opposition the balancing length is $$4 \mathrm{~m}$$. The ratio of the e.m.f. of the two cells $$\left(\frac{E_1}{E_2}\right)$$ is