Assertion ( A ): Moving iron instrument can be used on ac or dc.
Reason ( R ): In a moving iron instrument deflecting torque is proportional to square of current.
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true R is false
D. A is false R is true
Share your understanding of this question with the correct explanation.