A generator develops an e.m.f. of 120 V and has a terminal potential difference of 115 V, when the amature current is 25 A. What is the resistance of the armature ?

Can the terminal potential difference of a cell exceed its e.m.f. ?

The terminal potential difference of a cell when short-circuited is (E = E.M.F. of the cell)

The terminal potential difference for a cell is 8.5 V when current is 2A and 9 V when current is 1.5A. What is the internal resistance of cell ?

Potential difference between the two brushes of generator is found to be 200 V when current of 5 A is being delivered by it. When current delivered by the same generator is 10 A, then potentail difference between the brushes of generator becomes 180 V. What is the induced emf and resistance of armature coil ?

The brush potential of a separately excited generator, when it is delivering 5 A is 125 V. When the generator dilivers 15 A, the potential difference across the brushes fall to 122 V. What are the induced e.m.f. and the resistance of armature ?

In an experiment a student measures terminal potential difference (TPD) of a cell. When the same cell is connected to an external resistance of 5 Omega then the TPD is 2 V and when the same is repeated for an external resistance of 10 Omega then the TPD is 2.4 V. What is the emf and internal resistance of cell?

A motor having an armature of resistance 2.0 ohm operates on 220 V mains. At its full speed, it develops a back e.m.f. of 210 V. Find the currents in the armature when motor is switched on and when running at full speed. What is the efficiency ot the motor at full speed ?

An electric motor runs a D.C. source of e.m.f. 200 V and draws a current of 10A . If the efficiency is 40% , then ressistance of the armature is: