Question 11:
moderate
In an a.c. circuit V and I are given by
V = 100 sin (100 t) volts
I = 100 sin (100t + π/3) mA
The power dissipated in the circuit is
Question 12:
moderate
A condenser of capacity C is charged to a potential difference of V1. The plates of the condenser are then connected to an ideal inductor of inductance L. The current through the indictors when the potential difference across the condenser reduces to V2 is ?
Question 13:
moderate
The readings of ammeter and voltmeter in the following circuit are respectively :-
Question 14:
moderate
For given circuit, find effective impedance for frequencies much higher than resonating
frequency.
Question 15:
moderate
Which of the following plot correctly depicts the variation of phase difference between voltage and current in a series L-C AC circuit ?
1. 
2. 
3. 
4. 
Question 16:
moderate
When S1 is closed and S2 is open, \[V_{L}=V_{R}=V_{C}=10V\]. What will be the value of
\[V_{C}\] if S1 opened and S2 is closed ?
Question 17:
moderate
In the circuit of Figure, the volmeter reads 75 V.Value of C is :
Question 18:
moderate
A square wave current switching rapidly between \(+0.5\) ampere and \(-0.5\) ampere is passed through an A.C ammeter. Then the reading shown by it, is
An AC ammeter measures the RMS value of the current. For a symmetric square wave of amplitude \(I_0\), the RMS value is equal to its peak value, \(I_{rms} = I_0 = 0.5\text{ A}\).
Question 19:
moderate
In an LCR series circuit the potential differences across the resistance, capacitance and inductance are \(80\text{ V}\), \(40\text{ V}\) and \(100\text{ V}\) respectively. The power factor of this circuit is:
Total voltage in series LCR is \(V = \sqrt{V_R^2 + (V_L - V_C)^2} = \sqrt{80^2 + (100 - 40)^2} = 100\text{ V}\). Power factor is \(\cos\phi = \frac{V_R}{V} = \frac{80}{100} = 0.8\).