Question

An electric wire of length ‘I’ and area of cross-section $a$ has a resistance R ohms. Another wire of the same material having same length and area of cross-section 4a has a resistance of

• A. 4R
• B. R/4
• C. R/16
• D. 16R

Answer 1

Answer: (B)

R/4

Answer 2

$R = \frac{\rho l}{a}$ for first wire and R’=$\frac{\rho l}{4a} = \frac{R}{4}$for second wire.