Question

A voltmeter and an ammeter are used to respectively monitor the voltage across and the current through a resistor connected to an AC source. If the resistor has a value of 12.5 Ω and the ammeter reads 7.60 A, determine the following.
(a)

the rms voltage (in V) across the resistor

(b)

the peak voltage (in V) of the source

(c)

the maximum current (in A) in the resistor

(d)

the average power (in W) delivered to the resistor

Answer 1

Answer:

(a) 95 volt

(b)  134.33 volt

(c) 10.746 volt

(d) Average delivered power is 722 watt  

Explanation:

We have given value of resistance R = 12.5 ohm

Current in the ammeter i = 7.60 A

(a) Rms voltage in the resistor $V=iR=7.6\times 12.5=95volt$

(b) We know that rms voltage is given by $v_r=\frac{v_m}{\sqrt{2}}$

$v_m=\sqrt{2}v_r=1.414\times 95=134.33volt$

So peak voltage will be equal to 134.33 volt

(c) Maximum current is equal to $i_m=\sqrt{2}i_r=1.414\times 7.6=10.746A$

(d) Average power delivered in the resistor is equal to

P = VI

So $P=95\times 7.6=722watt$