Question

AB is a wire of potentiometer with the increase in the value of resistance R, the shift in the balance point J will be

Answer 1

Answer:

If R is increased current in main circuit will decrease (by V= IR) as the potential (E) is constant. So in turn potential difference across AB will decrease (by V=IR). As R of AB is constant so potential gradient will decrease. So to balance potential across AB equal to potential of secondary circuit (E’) the length AJ’ must be larger than earlier AJ. So the point J shifts towards B.