Question

Write an expression for the instantaneous voltage ?(?) delivered by an ac generator supplying 120 V rms at 70 Hz. Assume the voltage is 0 at time ?=0, and leave the factors in exact form; do not round their values. Write the argument of the sinusoidal function to have units of radians, but omit the units.

Answer 1

solution : As we know that

and = ​ and ​​​​​​

  where is instantaneous voltage , is maximum voltage , is angular frequency , is time and is initial phase or argument, is root mean square of voltage , is frequency of a.c. generator.

Given ; ; at       ;

  

hence, = 0;

  

     (putting value of and = 22/7)

hence