R4RIN – MCQs, Mock Tests | Electrical engineering Network Theory Set-4

If there are M meshes, B branches and N nodes including reference node, the number of mesh currents is given as M=?

1. B + (N+1)
2. B + (N-1)
3. B-(N+1)
4. B-(N-1)

✅ Correct Answer: 4

If there are N nodes in a circuit, then the number of nodal equations that can be formed are?

1. N+1
2. N
3. N-1
4. N-2

✅ Correct Answer: 3

Superposition theorem states that the response in any element is the ____________ of the responses that can be expected to flow if each source acts independently of other sources.

1. algebraic sum
2. vector sum
3. multiplication
4. subtraction

✅ Correct Answer: 2

Superposition theorem is valid for only linear systems.

1. true
2. false
3.
4.

✅ Correct Answer: 1

Thevenin’s voltage is equal to the _____________ voltage across the _______________ terminals.

1. short circuit, input
2. short circuit, output
3. open circuit, output
4. open circuit, input

✅ Correct Answer: 3

Norton’s current is equal to the current passing through the ___________ circuited ___________ terminals.

1. short, input
2. short, output
3. open, output
4. open, input

✅ Correct Answer: 2

The condition for maximum voltage to be transferred to the load is?

1. Source resistance greater than load resistance
2. Source resistance less than load resistance
3. Source resistance equal to load resistance
4. Source resistance greater than or equal to load resistance

✅ Correct Answer: 2

The condition for maximum current to be transferred to the load is?

1. Source resistance greater than or equal to load resistance
2. Source resistance equal to load resistance
3. Source resistance less than load resistance
4. Source resistance greater than load resistance

✅ Correct Answer: 4

The condition for maximum power to be transferred to the load is?

1. Source resistance equal to load resistance
2. Source resistance greater than load resistance
3. Source resistance greater than or equal to load resistance
4. Source resistance less than load resistance

✅ Correct Answer: 1

At resonant frequency, the voltage across capacitor is _______ the voltage across inductor.

1. greater than
2. less than
3. greater than or equal to
4. equal to

✅ Correct Answer: 4

The voltage across the LC combination in a series RLC circuit is?

1. 0
2. 1
3. 2
4. 3

✅ Correct Answer: 1

The expression of resonant frequency in a series resonant circuit is?

1. 1/(2π√C)
2. 1/( 2π√L)
3. 2π√LC
4. 1/(2π√LC)

✅ Correct Answer: 4

Determine the resonant frequency for the specifications: R = 10Ω, L = 0.1H, C = 10µF.

1. 157
2. 158
3. 159
4. 160

✅ Correct Answer: 3

The expression for bandwidth is?

1. R/πL
2. R/2πL
3. R/4πL
4. R/8πL

✅ Correct Answer: 2

If a series circuit contains resistor and capacitor, the expression for quality factor is?

1. C
2. ωRC
3. ωC
4. 1/ωRC

✅ Correct Answer: 4

The quality factor of the coil for a series circuit having R = 10Ω, L = 0.1H, C = 10µF.

1. 1
2. 5
3. 10
4. 15

✅ Correct Answer: 3

The expression of resonant frequency for parallel resonant circuit is?

1. 1/(2π√LC)
2. 1/(π√LC)
3. 1/(2√LC)
4. 1/√LC

✅ Correct Answer: 1

If the value of Q of the circuit is high, then its effect on bandwidth is?

1. large bandwidth
2. small bandwidth
3. no effect on bandwidth
4. first increases and then decreases

✅ Correct Answer: 2

If in a circuit, if Q value is decreased then it will cause?

1. small bandwidth
2. no effect on bandwidth
3. first increases and then decreases
4. large bandwidth

✅ Correct Answer: 4

The expression of ωr in a parallel resonant circuit is?

1. 1/(2√LC)
2. 1/√LC
3. 1/(π√LC)
4. 1/(2π√LC)

✅ Correct Answer: 2

The expression of bandwidth for the parallel resonant circuit is?

1. 1/RC
2. RC
3. 1/R
4. 1/C

✅ Correct Answer: 1

The quality factor is the product of 2π and the ratio of ______ to _________

1. maximum energy stored, energy dissipated per cycle
2. energy dissipated per cycle, maximum energy stored
3. maximum energy stored per cycle, energy dissipated
4. energy dissipated, maximum energy stored per cycle

✅ Correct Answer: 1

A circuit tuned to a frequency of 1.5 MHz and having an effective capacitance of 150 pF. In this circuit, the current falls to 70.7 % of its resonant value. The frequency deviates from the resonant frequency by 5 kHz. Effective resistance of the circuit is?

1. 2 Ω
2. 3 Ω
3. 5.5 Ω
4. 4.7 Ω

✅ Correct Answer: 4

A 50 μF capacitor, when connected in series with a coil having a resistance of 40Ω, resonates at 1000 Hz. The inductance of the coil for the resonant circuit is ____________

1. 2.5 mH
2. 1.2 mH
3. 0.5 mH
4. 0.1 mH

✅ Correct Answer: 3

A coil (which can be modelled as a series RL circuit) has been designed for a high Quality Factor (Q) performance. The voltage is rated at and a specified frequency. If the frequency of operation is increased 10 times and the coil is operated at the same rated voltage. The new value of Q factor and the active power P will be?

1. P is doubled and Q is halved
2. P is halved and Q is doubled
3. P remains constant and Q is doubled
4. P decreases 100 times and Q is increased 10 times

✅ Correct Answer: 4

A 440 V, 50 HZ AC source supplies a series LCR circuit with a capacitor and a coil. If the coil has 100 mΩ resistance and 15 mH inductance, then at a resonance frequency of 50 Hz, the half power frequencies of the circuit are?

1. 50.53 Hz, 49.57 Hz
2. 52.12 HZ, 49.8 Hz
3. 55.02 Hz, 48.95 Hz
4. 50 HZ, 49 Hz

✅ Correct Answer: 1

At what frequency will the current lead the voltage by 30° in a series circuit with R = 10Ω and C = 25 μF?

1. 11.4 kHz
2. 4.5 kHz
3. 1.1 kHz
4. 24.74 kHz

✅ Correct Answer: 1

A 440 V, 50 HZ AC source supplies a series LCR circuit with a capacitor and a coil. If the coil has 100 mΩ resistance and 15 mH inductance, then at a resonance frequency of 50 Hz, what is the value of the capacitor?

1. 676 μF
2. 575 μF
3. 591 μF
4. 610 μF

✅ Correct Answer: 1

A 440 V, 50 HZ AC source supplies a series LCR circuit with a capacitor and a coil. If the coil has 100 mΩ resistance and 15 mH inductance, then at a resonance frequency of 50 Hz, the Q factor of the circuit is?

1. 82.63
2. 47.115
3. 27.38
4. 92.38

✅ Correct Answer: 2

A series RLC circuit has a resonance frequency of 1 kHz and a quality factor Q = 50. If R and L are doubled and C is kept same, the new Q of the circuit is?

1. 25.52
2. 35.35
3. 45.45
4. 20.02

✅ Correct Answer: 2

In a series RLC circuit for lower frequency and for higher frequency, power factors are respectively ______________

1. Leading, Lagging
2. Lagging, Leading
3. Independent of Frequency
4. Same in both cases

✅ Correct Answer: 1

For a parallel RLC circuit, the incorrect statement among the following is _____________

1. The bandwidth of the circuit decreases if R is increased
2. The bandwidth of the circuit remains same if L is increased
3. At resonance, input impedance is a real quantity
4. At resonance, the magnitude of input impedance attains its minimum value

✅ Correct Answer: 4

For a series RLC circuit, excited by voltage V = 20 sinωt. The values of R = 2 Ω, L = 1mH and C = 0.4 µF. The resonant frequency of the circuit is ______________

1. 20 krad/s
2. 30 krad/s
3. 40 krad/s
4. 50 krad/s

✅ Correct Answer: 4

For a series RLC circuit, excited by voltage V = 20 sinωt. The values of R = 2 Ω, L = 1mH and C = 0.4 µF. The quality factor and bandwidth of the circuit is ______________

1. 25, 2
2. 30, 5
3. 40, 10
4. 50, 2

✅ Correct Answer: 1

An ideal transformer is rated as 2400/120 V, 9.6 kVA and has 50 turns on the secondary side. The turns ratio is ____________

1. 0.04
2. 0.05
3. 0.06
4. 0.07

✅ Correct Answer: 2

A 50 μF capacitor, when connected in series with a coil having a resistance of 40Ω, resonates at 1000 Hz. The circuit is in resonating condition. The voltage across the capacitor is __________

1. 8.04 V
2. 7.96 V
3. 5.68 V
4. 1.25 V

✅ Correct Answer: 3

An ideal transformer is rated as 2400/120 V, 9.6 kVA and has 50 turns on the secondary side. The number of turns on the primary side is ____________

1. 1000
2. 2000
3. 3000
4. 4000

✅ Correct Answer: 1

A 50 μF capacitor, when connected in series with a coil having resistance of 40Ω, resonates at 1000 Hz. The circuit current if the applied voltage is 100 V for the resonant circuit is ___________

1. 2.5 A
2. 3.5 A
3. 4.5 A
4. 0.5 A

✅ Correct Answer: 1

A 50 μF capacitor, when connected in series with a coil having resistance of 40Ω, resonates at 1000 Hz. The circuit is in resonating condition. The voltage across the coil is __________

1. 100.31 V
2. 200.31 V
3. 300.31 V
4. 400.31 V

✅ Correct Answer: 1

A series RLC circuit has a resonance frequency of 1 kHz and a quality factor Q = 100. If each of R, L and C is doubled from its original value, the new Q of the circuit is _____________

1. 25
2. 50
3. 100
4. 200

✅ Correct Answer: 2

The current through an electrical conductor is 1A when the temperature of the conductor 0°C and 0.7 A when the temperature is 100°C. The current when the temperature of the conductor is 1200°C is ___________

1. 0.08 A
2. 0.16 A
3. 0.32 A
4. 0.64 A

✅ Correct Answer: 2

An air capacitor of capacitance 0.005 μF is connected to a direct voltage of 500 V. It is disconnected and then immersed in oil with a relative permittivity of 2.5. The energy after immersion is?

1. 275 μJ
2. 250 μJ
3. 225 μJ
4. 625 μJ

✅ Correct Answer: 2

A capacitor of capacitance 50 μF is connected in parallel to another capacitor of capacitance 100 μF. They are connected across a time-varying voltage source. At a particular time, the current supplied by the source is 5 A. The magnitude of instantaneous current through the capacitor of capacitance 50 μF is?

1. 1.57 A
2. 1.87 A
3. 1.67 A
4. 2.83 A

✅ Correct Answer: 3

A capacitor of capacitance 50 μF is connected in parallel to another capacitor of capacitance 100 μF. They are connected across a time-varying voltage source. At a particular time, the current supplied by the source is 5 A. The magnitude of instantaneous current through the capacitor of capacitance 100 μF is?

1. 2.33 A
2. 3.33 A
3. 1.33 A
4. 4.33 A

✅ Correct Answer: 2

The voltage drop across a standard resistor of 0.2 Ω is balanced at 83 cm. The magnitude of the current, if the standard cell emf of 1.53 V is balanced at 42 m is ___________

1. 13.04 A
2. 10 A
3. 14.95 A
4. 12.56 A

✅ Correct Answer: 3

The simultaneous applications of signals x (t) and y (t) to the horizontal and vertical plates respectively, of an oscilloscope, produce a vertical figure of 8 displays. If P and Q are constants and x(t) = P sin (4t + 30), then y(t) is equal to _________

1. Q sin (4t – 30)
2. Q sin (2t + 15)
3. Q sin (8t + 60)
4. Q sin (4t + 30)

✅ Correct Answer: 2

A resistor of 10 kΩ with a tolerance of 5% is connected in parallel with 5 kΩ resistors of 10% tolerance. The tolerance limit is __________

1. 9%
2. 12.4%
3. 8.33%
4. 7.87%

✅ Correct Answer: 3

A 200/1 Current Transformer (CT) is wound with 400 turns on the secondary on a toroidal core. When it carries a current of 180 A on the primary, the ratio is found to be -0.5%. If the number of secondary turns is reduced by 1, the new ratio error (in %) will be?

1. 0.0
2. -0.5
3. -1.0
4. -2.0

✅ Correct Answer: 3

In the Two wattmeter method of measuring power in a balanced three-phase circuit, one wattmeter shows zero and the other positive maximum. The load power factor is ___________

1. 0
2. 0.5
3. 0.866
4. 1.0

✅ Correct Answer: 2

The meter constant of a single-phase, 230 V induction watt-meter is 600 rev/kW-h. The speed of the meter disc for a current of 15 A at 0.8 power factor lagging will be?

1. 30.3 rpm
2. 25.02 rpm
3. 27.6 rpm
4. 33.1 rpm

✅ Correct Answer: 3