Physics And Measurement Question 295
Question: The resistance of a metal is given by $ R=\frac{V}{I} $ where V is potential difference and I is the current. In a circuit the potential difference across resistance is $ V=(8\pm 0.5)V $ and current in resistance $ I=(2\pm 0.2)A $ . What is the value of resistance with its percentage error?
Options:
A) $ 4\Omega \pm 16.25% $
B) $ (4\pm 0.7)\Omega $
C) $ 4\Omega \pm 0.7% $
D) $ 4\Omega \pm 7% $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] Actual $ R=\frac{8}{2}=4 $ % error in R =% error in V+% error in I $ =\frac{0.5}{8}\times 100%+\frac{0.2}{2}\times 100%=16.25% $
$ R=4\Omega \pm 16.25% $
