Electro Magnetic Induction And Alternating Currents Question 502
Question: A simple electric motor has an armature resistance of and runs from a dc source of 12 volt. When running unloaded it draws a current of 2 amp. When a certain load is connected, its speed becomes one-half of its unloaded value. What is the new value of current drawn?
Options:
A) 7 A
B) 3 A
C) 5 A
D) 4 A
Show Answer
Answer:
Correct Answer: A
Solution:
-
Let initial e.m.f. induced =e
Initial current i.e.,This gives
volt. As .when speed is halved, the value of induced e.m.f. becomes
New value of current