A 40-W instrument has a resistance of 90(Omega). On what voltage should it be operated normally?
-
A.
60V -
B.
150V -
C.
225V -
D.
3600V
Correct Answer: Option A
Explanation
P = (frac{V}{R})
V = (sqrt{PR})
V = (sqrt{40 times 90})
= 60V
P = (frac{V}{R})
V = (sqrt{PR})
V = (sqrt{40 times 90})
= 60V