Work Energy And Power Question 264
Question: If two persons A and B take 2 seconds and 4 seconds respectively to lift an object to the same height h, then the ratio of their powers is
Options:
A) 1:2
B) 1:1
C) 2:1
D) 1:3
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ Power=\frac{work done}{time} $
Therefore power of A, $ {P _{A}}=\frac{mgh}{t _{A}} $ and power of B, $ {P _{B}}=\frac{mgh}{{t _{B}}} $
$ \therefore \frac{P _{A}}{P _{B}}=\frac{t _{B}}{t _{A}}=\frac{4}{2}=2:1 $
