A potentiometer wire has length 4 m and resistance 8 ohm. The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2V, so as to get a potential gradient 1 mV per cm on the wire is:
44 ohm
48 ohm
32 ohm
40 ohm
As we learnt in
Potential gradient -
- wherein
internal resistance
So for 400 cm
Option 1)
44 ohm
Incorrect
Option 2)
48 ohm
Incorrect
Option 3)
32 ohm
Correct
Option 4)
40 ohm
Incorrect