1.

There is a potentiometer wire of length 1200 cmand a 60 mA curreut is flowing in it. A battery of emf 5 V and internal resistance of 20 Omegais balanced on this potentiometer wfre with a balancing length 1000 cm. The resistance of the potentiometer wire is

Answer»

`60 Omega`
`80 Omega`
`1000 Omega`
`120 Omega`

Solution :`100 Omega`

LET terminal voltage of PRIMARY BATTERY is`V_(p)`. For any neutral point on potentiometer wire, `V_(p)` remains constant .
`therefore ` potential GRADIENT,
`(V)/(l) = (V_(p))/(L)`
`therefore (5)/(1000) = (V_(p))/(1200)`
`therefore= (1200 xx 5)/(1000) = 6V`
`therefore ` Resistance of potentiometer wire
`R_(p) = (V_(p))/(I)`
`thereforeR_(p) = (6)/(60 xx 10^(-3)) `
`therefore R_(p) =100 Omega`


Discussion

No Comment Found

Related InterviewSolutions