The figure shows the time variation of the magnitude of the electric field of an electromagnetic wave produced by a wire antenna.
-Determine the rms value of the electric field magnitude.
A)7.1 N/C
B)12 N/C
C)14 N/C
D)19 N/C
E)28 N/C

Question

The figure shows the time variation of the magnitude of the electric field of an electromagnetic wave produced by a wire antenna. 
-Determine the rms value of the electric field magnitude.
A)7.1 N/C 
B)12 N/C 
C)14 N/C 
D)19 N/C 
E)28 N/C

Quizplus · Accepted Answer

The rms value of the electric field magnitude is given by:$$E_{rms}=\sqrt{\frac{1}{2}}E_0$$where $E_0$ is the peak value of the electric field magnitude. In this case, $E_0=14 N/C$, so:$$E_{rms}=\sqrt{\frac{1}{2}}(14 N/C)=7.1 N/C$$

The Figure Shows the Time Variation of the Magnitude of the Electric