- Find i(t) when V
_{S}(t) = 100 sin(2510 t).Z_{eq}= 10 ω i(t) = V_{S}/ 10 = 10 sin(2510t). - What is h(t) in following circuit ?
Step response is given as [1 – e
^{ -α t}]u(t)

h(t) is an impulse response.

- In a pure parallel LC circuit under resonance condition, current drawn from main supply is
Current in LC circuit is 0 at resonance, because of infinite of parallel LC circuit.
- Z may comprise of following circuit
Series combination of 2.5 mH & 16&mm; F will result in a lossless resonant L-C circuit with constant V.

But parallel combination of 2.5 mH & 16 μ F will result in an exponentially increasing sinusoidal response as shown. - In a RLC circuit (series) if C is increasing & remaining R & L are constants, then resonant frequency will be
As resonant frequency, f
_{0},

- If all the transmission zeros of a network are at infinity then it is a
lim T(s) = 0

s → ∞

So it will be a low pass filter. - At lower half power frequency current in series R-L-C circuit has the phase relation with reference to supply voltage as
- A circuit with a resistor, inductor and capacitor in series is resonant of f
_{0}Hz. If all the component values are now doubled the new resonant frequency isResonant frequency, f_{0},

- In a series RLC high Q circuit, the current peaks at a frequency

Now high Q means low R, C & high L.

So bandwidth = f_{0}/Q

Since less bandwidth, hence sharp resonance. - A sinusoidal voltage V & frequency f connected to a series circuit at variable resistance R and a fixed reactance X. The locus of the tip of the current phase or I as R is varied from zero to infinity is

Above equation is a semicircle equation with radius V/2X. - In the network shown below, switch S was closed & steady state is a attained. If S is opened at t = 0 & i(t) = 2 cos 100t then what is the value of V ?
Circuit starts oscillating when switch is opened.

Here I = 2, R = 2.5 Ω. - Circuit shown below has been in steady state when switch S is opened, the current I is given by
When the switch is closed and circuit reached its steady state condition. Since inductor offers short circuit path. So

I = 10 / 1 = 10A

Now, when switch is opened,

- The current i(t) at any instant t in the network shown in the figure will be after closing the switch S at t = 0
The value of the current at t = 0
^{ + }and at t = infinity; which should be zero and 10 / 1 = 10 A respectively. - A series RLC circuit consisting of R = 20 ohms X
_{L}= 20 ohms is connected across an ac supply of 200 V rms. The rms voltage across the capacitor is

Z = 20 ohms

I = 200 / 20 = 10 A

V_{C}= –JIX_{C}. - In a RC circuit consisting R = 10KΩ &phase angle between current &voltage is 45° What is the value of C at Ω = 1 ?
&theata; = tan
^{ - 1}(X^{C}/R)

So, X^{C}/R = 1

X^{C}= 10 KΩ

or, 1/ C = 10KΩ. - In a series RLC circuit the phasor diagram shown as below. Which of following is true regarding phasor diagram for the series RLC circuit ?
Here V
_{C}> V_{L}, 1/Ω C > Ω L. - In a RLC series circuit consisting V
_{R}= 3V, V V_{C}=8V & V V_{L}= 4 V, Find the value of source excitation voltage ?. - In a parallel RL Circuit has i = 10A *amp; i V
_{R}= 8A. Find the value of current flowing through the inductor ?. - If a capacitor is added in parallel with inductor C in the above question, which draws a current of 6A then i will be
.
- Consider the following circuit diagram. If R = 25Ω X V
_{L}= X V_{C}= 25Ω then what is the value of &theata; j ? [Assuming V as reference phasor]tan&theata; = X V_{L}/R.