Home
Class 12
PHYSICS
A capacitor and a resistor are connected...

A capacitor and a resistor are connected in sereis with an AC source. If the potential difference across C and R are 120 V and 90 V respectively if the rsm current of the is 3A, calculate the (a) impedance. (b) power factor of the circuit.

Text Solution

Verified by Experts

Here,
Potential difference across C is `V_(C ) = 120 V`
Potential difference across `V_(R ) = 90V`
Rms current in circuit, `I_(rms) = 3A`
So, rms voltage `V_(rms)=sqrt(V_(C)^(2) + V_(R)^(2))`
`=sqrt((120)^(2)+(90)^(2)150V`
(a) Impedance, Z = `(V_(rms))/(I_(rms))`
`rArr " " Z=(150)/(3)=50 Omega`
(b) Powr factor, `cos phi = (R )/(Z)`
`=(l_(rms))/(l_(rms))(R)/(Z)=(V_(R))/(V_(rms))=(90)/(150)=0.6`
Promotional Banner

Similar Questions

Explore conceptually related problems

A capacitor and resistor are connected in series with an ac source. If the potential difference across C and R are 120 V and 90V respectively and if the rms current of the circuit is 3A, calculate (i) impedance and (ii) power factor of the circuit.

A 25 µ F capacitor, a 0.1 henry inductor and a 25 Ω resistor are connected in series with an ac source with voltage. V = 310 sin 314t. (a) What is the frequency of the voltage ? (b) Calculate the reactance and impedance and (c) current in the circuit.

An inductor 20 mH, a capacitor 50 μF and a resistor 40 Ω are connected in series across a source of emf V=10sin340t. Calculate the power loss in A.C. circuit