Electro Magnetic Induction And Alternating Currents Question 238
Question: An electric motor operates on a 50 volt supply and a current of 12A. If the efficiency of the motor is 30%, what is the resistance of the winding of the motor [Kerala PET 2002]
Options:
A) $ 6\Omega $
B) $ 4\Omega $
C) $ 2.9\Omega $
D) $ 3.1\Omega $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \eta =\frac{e}{E}\times 100\Rightarrow e=0.3\ E $
Now, $ i=\frac{E-e}{R}\Rightarrow 12=\frac{50-(0.3\times 50)}{R}\Rightarrow R=2.9\Omega $
BETA
