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.