Question

A 70 Ω resistor is connected to an ac source generating an emf ‘e’ given by e(V) = 495 Sin(100 πt).

Calculate rms value of the current (I_rms) flowing through the resistor.

Answer 1

Given: Resistance (R) = 70 Ω

emf e(t) = 495 Sin(100 πt)

Formula: e = E₀ sin(ωt)

From the equation, the peak voltage is:

E₀ = 495 V

The root-mean-square (RMS) value of the voltage is related to the peak value by:

`E_"rms" = (E_0)/sqrt2`

= `495/1.1414`

= 350 V

Using Ohm’s Law for an AC circuit with a pure resistor.

`I_"rms" = E_"rms"/R`

= `350/70`

= 5 A