CLASS 12 PHYSICS
ATOQ
- In an AC circuit, the direction of current changes:
a) periodically
b) continuously
c) randomly
d) never - The frequency of AC in India is:
a) 50 Hz
b) 60 Hz
c) 100 Hz
d) 120 Hz - Which device is used to measure AC voltage?
a) Ammeter
b) Voltmeter
c) Ohmmeter
d) Wattmeter - The peak value of AC voltage is 220V. What is its RMS value?
a) 220V
b) 110V
c) 154V
d) 311V - In an AC circuit, the power factor is the angle between:
a) Voltage and resistance
b) Voltage and current
c) Resistance and current
d) Resistance and reactance - The unit of reactance is:
a) Ohms
b) Farads
c) Henrys
d) Hertz - In a purely resistive AC circuit, the power factor is:
a) 0
b) 1
c) -1
d) 0.5 - Which component of AC impedance depends on frequency?
a) Resistance
b) Inductance
c) Capacitance
d) Conductance - The phase difference between voltage and current in a purely capacitive circuit is:
a) 0 degrees
b) 90 degrees
c) 180 degrees
d) 270 degrees - A coil has an inductance of 2 H. What is its reactance at 50 Hz?
a) 50 Ω
b) 100 Ω
c) 200 Ω
d) 500 Ω - Which type of circuit has both resistance and capacitance?
a) RL circuit
b) RC circuit
c) LC circuit
d) RLC circuit - The peak current in an AC circuit is 5A. What is the RMS current?
a) 2.5A
b) 5A
c) 7.07A
d) 10A - Which device converts AC to DC?
a) Transformer
b) Capacitor
c) Diode
d) Inductor - What is the voltage across a resistor connected in series with a capacitor in an AC circuit?
a) Equal to the supply voltage
b) Greater than the supply voltage
c) Less than the supply voltage
d) Zero - The reactance of an inductor in an AC circuit is directly proportional to:
a) Inductance
b) Current
c) Frequency
d) Resistance - What happens to the impedance of a resistor in an AC circuit as the frequency increases?
a) Increases
b) Decreases
c) Remains constant
d) Depends on the resistance value - Which type of wave does AC voltage follow?
a) Sine wave
b) Square wave
c) Triangle wave
d) Sawtooth wave - In a series RLC circuit, resonance occurs when:
a) XL = XC
b) XL > XC
c) XL < XC
d) Resistance is maximum - The power dissipated in an AC circuit is given by:
a) P = VI
b) P = V^2/R
c) P = I^2R
d) P = V^2/X - Which parameter of AC voltage determines its magnitude?
a) Amplitude
b) Frequency
c) Phase angle
d) Wavelength