In a series R-L-C circuit, the frequency of the source is half of the resonance frequency. The name of the circuit will be:
1. capacitive
2. inductive
3. purely resistive
4. data insufficient
In the given figure, a lamp P is in series with an iron-core inductor L. When the switch S is closed, the brightness of the lamp rises relatively slowly to its full brightness than it would do without inductor in circuit. This is due to:
1. the low resistance of P
2. the induced emf in L
3. the low resistance of L
4. the low voltage of the battery B
The reactance of a circuit is zero. It is possible that the circuit contains:
1. an inductor and a capacitor
2. an inductor but no capacitor
3. a capacitor but no inductor
4. All of the above
If the RMS current in a \(50~\text{Hz}\) AC circuit is \(5~\text{A}\), the value of the current \(\frac{1}{300}~\text{s}\) after its value becomes zero is:
1. \(5\sqrt2~A\)
2. \(5\sqrt{\frac32}~A\)
3. \(\sqrt{\frac56}~A\)
4. \(\frac{5}{\sqrt2}~A\)
An alternating current generator has an internal resistance and an internal reactance . It is used to supply power to a passive load consisting of a resistance and a reactance . For maximum power to be delivered from the generator to the load, the value of is equal to :
1. zero
2. Xg
3. -Xg
4. Rg
When a voltage measuring device is connected to AC mains, the meter shows the steady input voltage of \(220~\text{V}\). This means:
1. | input voltage cannot be AC voltage, but a DC voltage |
2. | maximum input voltage is \(220~\text{V}\) |
3. | the meter reads not v but \(<v^2>\) and is calibrated to read \(\sqrt{<v^2>}\) |
4. | the pointer of the meter is stuck by some mechanical defect |
To reduce the resonant frequency in an LCR series circuit with a generator:
1. | the generator frequency should be reduced |
2. | another capacitor should be added in parallel to the first |
3. | the iron core of the inductor should be removed |
4. | the dielectric in the capacitor should be removed |
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. \(18~\text{W}\)
The output of a step-down transformer is measured to be 24 V when connected to a 12 W light bulb. The value of the peak current is:
1. 1/ A
2. A
3. 2 A
4. 2A
As the frequency of an AC circuit increases, the current first increases and then decreases. What combination of circuit elements is most likely to comprise the circuit?
(a) Inductor and capacitor
(b) Resistor and inductor
(c) Resistor and capacitor
(d) Resistor, inductor, and capacitor
Choose the correct option.
1. (b, c)
2. (c, d)
3. (b, d)
4. (a, d)