|1 Crore+ students have signed up on EduRev. Have you?|
Find the total voltage applied in a series RLC circuit when i=3mA, VL=30V, VC=18V and R=1000 ohms.
Explanation: Total voltage= VR+VL+VC.
Therefore, total voltage = 30+18+3=51V.
The power factor of an RL circuit 1/root2. If the frequency of a.c. is doubled, what will be the power factor?
When an emf E = 7cos wt is applied across a circuit, the current is I = 5coswt. What is the power factor for the circuit?
Since E and I are in the same phase.
Therefore, phase difference will be 0 and since power factor= cosx (where x= phase difference) and x =0
therefore, cos x or power factor will be =1
What is value of power factor if Ø = 90°
P=Irms Vrms cos ϕ
hence the correct answer is option A.
If the instantaneous current in a circuit is given by i = 2 cos (ωt - φ) A, the rms value of the current is
Find the true power given apparent power = 10 W and power factor = 0.5
The formula of true power is,
True power=Apparent power x power factor
So, true power=10 x 0.5
What is the average power/cycle in a capacitor?
The average power consumed/cycle in an ideal capacitor is 0.
The average power consumed in an ideal capacitor is given as based on the instantaneous power which is supplied to the capacitor:
pc = iv= (im cos ωt)(vm sin ωt)
pc = imvm (cos ωt sin ωt)
We know that sin ωt = 0
Therefore, average power = 0
What is phase angle given R = 10, Z = 20
Cos x (power factor) = R/Z
In a circuit, the reactance X and resistance R are equal. What is the power factor?
Reactance (X) =Resistance (R)
tanϕ = X/R
So, we have ϕ = π/4
Power factor = cosϕ = 1/√2