A cell of emf E and internal resistance r is connected to two external resistances $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ and a perfect ammeter. The current in the circuit is measured in four different situations:
(a) without any external resistance in the circuit.
(b) with resistance $$\mathrm{R_1}$$ only
(c) with $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ in series combination.
(d) with $$\mathrm{R_1}$$ and $$\mathrm{R_2}$$ in parallel combination.
The currents measured in the four cases in ascending order are
The current through a conductor is '$$\mathrm{a}$$' when the temperature is $$0^{\circ} \mathrm{C}$$. It is '$$\mathrm{b}$$' when the temperature is $$100^{\circ} \mathrm{C}$$. The current through the conductor at $$220^{\circ} \mathrm{C}$$ is
On increasing the temperature of a conductor, its resistance increases because
A galvanometer having a resistance of $$8 \Omega$$ is shunted by a wire of resistance $$2 \Omega$$. If the total current is $$1 \mathrm{~A}$$, the part of it passing through the shunt will be