Question

The frequency of an alternating voltage is 50 cycles/sec and its amplitude is 120V. Then the r.m.s. value of voltage is

• A. 101.3V
• B. 84.8V
• C. 70.7V
• D. 56.5V

Answer 1

Answer: (B)

84.8V

Answer 2

$V _ { r m s } = \frac { V _ { 0 } } { \sqrt { 2 } } = \frac { 120 } { 1.414 } = 84.8 \mathrm {~V}$