Question

What reading would you expect of a square-wave current, switching rapidly between $+0.5A$ and $-0.5A$, when passed through an ac ammeter?

• A. $0$
• B. $0.5A$
• C. $0.25A$
• D. $1.0A$

Answer 1

Answer: (B)

$0.5A$

AC ammeter reads the rms value.

rms value of current=$\sqrt{\frac{0.5T(+0.5{)}^2+0.5T(-0.5{)}^2}{T}}=\sqrt{{0.5}^2}=0.5A$