Current Electricity Charging Discharging Of Capacitors Question 168
Question: Length of a hollow tube is 5m, it’s outer diameter is 10 cm and thickness of it’s wall is 5 mm. If resistivity of the material of the tube is 1.7 ´ 10?8 W´m then resistance of tube will be
Options:
A) 5.6 ´ 10?5 W
B) 2 ´ 10?5 W
C) 4 ´ 10?5 W
D) None of these
Show Answer
Answer:
Correct Answer: A
Solution:
By using $ R=\rho .\frac{l}{A}; $ here $ A=\pi (r _{2}^{2}-r _{1}^{2}) $ Outer radius r2 = 5cm Inner radius r1 = 5 ? 0.5 = 4.5 cm So $ R=1.7\times {{10}^{-8}}\times \frac{5}{\pi {{{(5\times {{10}^{-2}})}^{2}}-{{(4.5\times {{10}^{-2}})}^{2}}}} $
$ =5.6\times {{10}^{-5}}\Omega $
BETA
