Alternating Current · Physics · AP EAPCET
MCQ (Single Correct Answer)
A coil of inductive reactance $\frac{1}{\sqrt{3}} \Omega$ and a resistance $1 \Omega$ are connected in series to a $200 \mathrm{~V}, 50 \mathrm{~Hz}$ AC source. The time lag between voltage and current is
An AC source of internal resistance $10^3 \Omega$ is connected to a transformer. The ratio of the number of turns in the primary to the number of turns in the secondary to match the source to a load resistance of $10 \Omega$ is
In a series LCR circuit, the voltages across the capacitor, resistor and inductor are in the ratio $2: 3: 6,$ if the voltage of the AC source in the circuit is 240 V , then the voltage across the inductor is
If the voltage and current in an AC circuit are respectively $50 \sin (50 t) \mathrm{V}$ and $50 \sin \left(50 t+\frac{\pi}{4}\right) \mathrm{mA}$, then the power dissipated in the circuit is nearly
In a series resonant LCR circuit, for the power dissipated to become half of the maximum power dissipated, the current amplitude is
If a resistor of resistance $4 \Omega$, a capacitor of capacitive reactance $6 \Omega$ and an inductor of inductive reactance $9 \Omega$ are connected in series with an AC source, then the impedance of the circuit is
A resistor of $450 \Omega$ and an inductor are connected in series to an AC source of frequency $\frac{75}{\pi} \mathrm{~Hz}$. If the power factor of the circuit is 0.6 , then the inductance connected in the circuit is
For better tuning of a series $L C R$ circuit in a communication system, the preferred combination is
In an LCR series circuit, if the potential differences across inductor, capacitor and resistor are $60 \mathrm{~V}, 30 \mathrm{~V}$ and 40 V respectively, then the AC voltage applied to the circuit is
The resonant frequency of an LC circuit is $f_0$. If a dielectric slab of constant 16 is inserted completely between the plates of the capacitor, then the resonant frequency is
A 50 Hz AC circuit has a 10 mH inductor and a $2 \Omega$ resistor in series. The value of capacitance to be placed in series in the circuit to make the circuit power factor as unity is
An $$R-L-C$$ circuit consists of a $$150 \Omega$$ resistor, $$20 \mu \mathrm{F}$$ capacitor and a 500 mH inductor connected in series with a 100 V AC supply. The angular frequency of the supply voltage is $$400 \mathrm{rad} \mathrm{s}^{-1}$$. The phase angle between current and the applied voltage is
Capacitive reactance of a capacitor in an AC circuit is $$3 \mathrm{k} \Omega$$. If this capacitor is connected to a new AC source of double frequency, the capacitive reactance will become.
A coil of inductance 0.1 H and resistance $$110 \Omega$$ is connected to a source of 110 V and 350 Hz . The phase difference between the voltage maximum and the current maximum is
A 20 V AC is applied to a circuit consisting of a resistor and a coil with negligible resistance. If the voltage across the resistor is 12 V, the voltage across the coil is
A bulb of resistance $$280 \Omega$$ is supplied with a 200 V AC supply. What is the peak current?
A resonant frequency of a current is $$f$$. If the capacitance is made four times the initial value, then the resonant frequency will become