Question

When a voltage measuring device is connected to ac mains, the meter shows the steady input voltage of 220 V. This means

• A. Input voltage cannot be ac voltage, but a dc voltage.
• B. Maximum input voltage is 220 V.
• C. The meter reads not V but $< V^{2} >$and is calibrated to read $\sqrt{< V^{2} >}$)
• D. The pointer of the meter is stuck by some mechanical defect.

Answer 1

Answer: (C)

The meter reads not V but $< V^{2} >$and is calibrated to read $\sqrt{< V^{2} >}$)

Answer 2

: The voltmeter connected to ac mains is calibrated to read root mean square value or virtual value of ac voltage.