A potentiometer wiere has a length of 4 and resistance of `20 Omega`. It is connected in series with resistance of `2980 Omega ` and a cell of emf 4 V. Calcaulte the potential along the wire.

Explanation

Given : The length of the potential wire 1=4 m
Resistors of the potential `r=20 Omega`
Resistor connected `R= 2980 Omega`
emf of the cell E =4V
To find :
potential along wire V= ?
Effective resistor r= & R are connected in series
`=2980+20=(r+R)`
`=3000 Omega`
Currret flowing through the wire `I=(xi)/(R)`
`I=(4)/(3000)`
Potential drop acress the wire `V=Ixxr`
`V=(4)/(3000)xx20=(8)/(300)` volt
Potential gradient `=("Potential drop")/("length")=(V)/(l)`
`=(8)/(300)xx(1)/(4)=(2)/(300)=0.66xx10^(-2) V m^(-1)`
Potential gradient `=0.66xx10^(-2)Vm^(-1)`