Question 1 |
In a series RLC circuit at resonance, the magnitude of the voltage developed
across the capacitor
is always zero | |
can never be greater than the input voltage | |
can be greater than the input voltage, however, it is 90^{\circ} out of phase with
the input voltage | |
can be greater than the input voltage, and is in phase with the input voltage. |
Question 1 Explanation:
In a series RLC circuit, at resonance
V_L=jQV_{source} and V_c=-jQV_{source}
also for Q \gt 1, |V_c| \gt |V_{source}|
Hence, option (C) is correct.
V_L=jQV_{source} and V_c=-jQV_{source}
also for Q \gt 1, |V_c| \gt |V_{source}|
Hence, option (C) is correct.
Question 2 |
Two incandescent light bulbs of 40 W and 60 W rating are connected in series
across the mains. Then
the bulbs together consume 100 W | |
the bulbs together consume 50W | |
the 60 W bulb glows brighter | |
the 40 W bulb glows brighter |
Question 2 Explanation:
\because \;\;P\propto \frac{1}{R}
Therefore , resistance of 40 W bulb \gt resistance of 60 W bulb.
For series connection, current through both the bulbs will be same P=I^2R (for series connection).
Power consumed by 40 W bulb \gtPower consumed by 60 W bulb.
Hencem the 40 W bulb glows brighter.
Therefore , resistance of 40 W bulb \gt resistance of 60 W bulb.
For series connection, current through both the bulbs will be same P=I^2R (for series connection).
Power consumed by 40 W bulb \gtPower consumed by 60 W bulb.
Hencem the 40 W bulb glows brighter.
Question 3 |
A unit step voltage is applied at t = 0 to a series RL circuit with zero initial
conditions.
It is possible for the current to be oscillatory. | |
The voltage across the resistor at t = 0^{+} is zero. | |
The energy stored in the inductor in the steady state is zero. | |
The resistor current eventually falls to zero. |
Question 3 Explanation:
At t=0^+ inductor works as open circuit. Hence, complete source voltage drops across it and consequently, current through the resistor R is zero. Hence, voltage across the resistor at t=0^+ is zero. And further with time it rises accroding to V_R(t)=(1-e^{-Rt/L})u(t).


Question 4 |
Given two coupled inductors L_{1} and L_{2}, their mutual inductance M satisfies
M=\sqrt{L^{2}_{1}+L^{2}_{2}} | |
M \gt \frac{\left ( L_{1}+L_{2} \right )}{2} | |
M\gt \sqrt{L_{1}L_{2}} | |
M\leq \sqrt{L_{1}L_{2}} |
Question 4 Explanation:
M=K\sqrt{L_1L_2}
where , K= coefficient of coupling
\because \; 0 \lt K \lt 1
\therefore \; M \leq \sqrt{L_1L_2}
where , K= coefficient of coupling
\because \; 0 \lt K \lt 1
\therefore \; M \leq \sqrt{L_1L_2}
Question 5 |
A passive 2-port network is in a steady-state. Compared to its input, the steady
state output can never offer
higher voltage | |
lower impedance | |
greater power | |
better regulation |
Question 5 Explanation:
For a passive two port network, output powe can never be grater than input power.
There are 5 questions to complete.