Two batteries of emf 4V and 8V with internal resistance are connected in a circuit with a resistance of as shown in figure. The current and potential difference between the point P and Q are
A potentiometer consists of a wire of length 4m and resistance . It is connected to a cell of emf 2 V. The potential gradient of the wire is
0.5 V/m
2 V/m
5 V/m
10 V/m
Kirchhoff's current law at a junction deals with conservation of
charge
energy
momentum
all of these
A 10 metre potentiometer wire has a resistance of 20 Ω. It is connected in series with a battery of emf 2.5 volt and a resistance of 5 Ω. The potential gradient along wire in volt cm-1 is
0.002
0.02
0.2
0.0025