Q. The specific resistance of manganin is $50 \times 10^{- 8}\ ohm \times m$. The resistance of a cube of length $50cm$ will be
A) $10^{- 6}\ ohm$
B) $2.5 \times 10^{- 5}\ ohm$
C) $10^{- 8}\ ohm$
D) $5 \times 10^{- 4}\ ohm$
Explanation
(a) $R = \frac{\rho l}{A} = 50 \times 10^{- 8} \times \frac{50 \times 10^{- 2}}{\left( 50 \times 10^{- 2} \right)^{2}} = 10^{- 6}\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.