The potential gradient along the length of a uniform wire is 10 volt / metre. B and C are the two points at 30 cm and 70 cm point on a metre scale fitted along the wire. What is the potential difference between B and C ?

Options

A. 3 V
B. 4 V
C. 5 V
D. 6 V

Answer

B

Explanation

Potential gradient `= 10 V//m =(10 V)/(100 cm)=(1)/(10)V//m`
`P.D. prop` length, Distance BC = 40 cm
`therefore P.D. =(1)/(10)xx 40 = 4V`