If the RMS current in a \(50~\text{Hz}\) AC circuit is \(5~\text{A}\), the value of the current \(\dfrac{1}{300}~\text{s}\) after its value becomes zero is:
1. | \(5\sqrt2~\text{A}\) | 2. | \(5\sqrt{\dfrac32}~\text{A}\) |
3. | \(\sqrt{\dfrac56}~\text{A}\) | 4. | \(\dfrac{5}{\sqrt2}~\text{A}\) |
An alternating current generator has an internal resistance \(R_{g}\) and an internal reactance \(X_{g}\). It is used to supply power to a passive load consisting of a resistance \(R_{g}\) and a reactance \(X_{L}\). For maximum power to be delivered from the generator to the load, the value of \(X_{L}\) is equal to:
1. zero
2. \(X_g\)
3. \(-X_g\)
4. \(R_g\)
Which of the following combinations should be selected for better tuning of an LCR circuit used for communication?
1. \(R = 20~\Omega,~L= 1.5~\text{H}, ~C = 35~\mu \text{F}\)
2. \(R = 25~\Omega,~L= 2.5~\text{H}, ~C = 45~\mu \text{F}\)
3. \(R = 15~\Omega,~L= 3.5~\text{H}, ~C = 30~\mu \text{F}\)
4. \(R = 25~\Omega,~L= 1.5~\text{H}, ~C = 45~\mu \text{F}\)
An inductor of reactance \(1~\Omega\) and a resistor of \(2~\Omega\) are connected in series to the terminals of a \(6~\text{V}\) (RMS) AC source. The power dissipated in the circuit is:
1. \(8~\text{W}\)
2. \(12~\text{W}\)
3. \(14.4~\text{W}\)
4. \(18~\text{W}\)
(a) | Inductor and capacitor |
(b) | Resistor and inductor |
(c) | Resistor and capacitor |
(d) | Resistor, inductor, and capacitor |
(a) | Only resistor |
(b) | Resistor and an inductor |
(c) | Resistor and a capacitor |
(d) | Only a capacitor |
Choose the correct options:
1. | (b), (c) | 2. | (a), (d) |
3. | (b), (d) | 4. | (c), (d) |
(a) | Here, the power factor \(\cos\phi \ge0, ~P \ge0.\) |
(b) | The driving force can give no energy to the oscillator \((P=0)\) in some cases. |
(c) | The driving force cannot syphon out \((P<0)\) the energy out of the oscillator. |
(d) | The driving force can take away energy out of the oscillator. |
(a) | the maximum voltage between plates is \(220\) V. |
(b) | the current is in phase with the applied voltage. |
(c) | the charge on the plates is in phase with the applied voltage. |
(d) | power delivered to the capacitor is zero. |
1. | (b), (c) | 2. | (a), (d) |
3. | (b), (d) | 4. | (c), (d) |