NBCC Executive Electrical Question Paper Part 4

Q.2 Two identical coils A and B of 1000 turns each lie in parallel plane such that 40% of the flux produced by one coil links with the other. If a current of 2 A flowing in A produces a flux of 0.02 mWb, then the flux linking with coil B is:

1. 0.08 mWb
2. 8 mWb
3. 0.8 mWb
4. 0.008 mWb

Correct Option: 1

NBCC Executive Electrical Question Paper Part 4

Q.3 Calculate the effective resistance (in ohms) of an RLC resonant circuit has a resonance frequency of 2 MHz and a bandwidth of 10 KHz if the capacitance is 100 pF.

1. 2.87
2. 4.98
3. 3.98
4. 3.79

Correct Option: 3

Q.6 Why are brass pins preferred over other materials for batten wiring applications in some environments?

1. Brass pins have high corrosion resistance
2. Brass pins are lightweight
3. Brass pins are non-conductive
4. Brass pins are cheaper than other materials

Correct Option: 1

NBCC Executive Electrical Question Paper Part 4

Q.7 What characterizes a load bus in load flow analysis?

1. It does not have any loads connected to it
2. It has variable voltage and power specifications
3. It has fixed voltage and power specifications
4. It is always connected to a slack bus

Correct Option: 3

Q.8 What is the main function of a Residual Current Device (RCD) in electrical installations?

1. To regulate voltage levels
2. To increase electrical resistance
3. To monitor and trip in the event of current leakage
4. To provide backup power during outages

Correct Option: 3

Q.9 How does the presence of eddy currents affect the inductance of a coil in a high-frequency magnetic field?

1. It increases the inductance
2. It reverses the direction of inductance
3. It has no effect on the inductance
4. It decreases the inductance

Correct Option: 4

Q.10 In older alternator designs, what components were commonly used for transferring electrical output from the rotor to external circuits?

1. Transistors
2. Soldered joints
3. Diodes
4. Brushes and slip rings

Correct Option: 4

NBCC Executive Electrical Question Paper Part 4

Q.11 A 5000 Ω variable resistance has a linearity of 0.2% and the movement of contact arm is 320°. Determine the maximum position deviation in degrees and the resistance deviation in ohm.

1. 0.64°, 10 Ω
2. 0.32°, 5 Ω
3. 0.48°, 5 Ω
4. 0.32°, 10 Ω

Correct Option: 1

Q.12 The dead zone in a certain pyrometer is toget 0.135 percent of span. The calibration is 600°C to 1200°C. What temperature change might occur before it is detected?

1. 0.68°
2. 0.34°
3. 0.81°
4. 0.75°

Correct Option: 3

Q.13 If a scientist repeats a measurement multiple times and obtains slightly different results with each trial, what type of error is likely present?

1. Systematic error
2. Instrumental error
3. Random error
4. Absolute error

Correct Option: 3

Q.15 Why should only authorized personnel have access to electrical panels and switchgear?

1. To keep the electrical equipment clean
2. To minimize electrical resistance
3. To improve equipment aesthetics
4. To reduce the risk of unauthorized and potentially unsafe operations

Correct Option: 4

NBCC Executive Electrical Question Paper Part 4

Q.16 In lighting design, what is the term for the uniform distribution of light across a surface?

1. Uniformity
2. Luminance
3. Glare
4. Candela

Correct Option: 1

Q.18 Which algorithm is commonly used to solve the Economic Load Dispatch problem?

1. Breadth-first search
2. Lambda iteration method
3. Gradient descent
4. Depth-first search

Correct Option: 2

Q.19 What is the main purpose of busbars in a distribution substation?

1. To store excess electrical energy
2. To provide seating for substation personnel
3. To enhance substation aesthetics
4. To facilitate the connection of electrical equipment

Correct Option: 4

NBCC Executive Electrical Question Paper Part 4

Q.20 Which type of compensator introduces a phase advance in the system’s frequency response?

1. Proportional-Integral-Derivative (PID) controller
2. Lead compensator
3. Lag compensator
4. Derivative controller

Correct Option: 2

Q.22 Which of the following is NOT the characteristic of Common source FET amplifier at high frequencies?

1. Voltage gain is frequency independent and complex in nature
2. Load impedance for the amplifier at high frequencies is always complex
3. Input impedance is finite and frequency dependent
4. Input impedance or input admittance is capacitive in nature

Correct Option: 1

NBCC Executive Electrical Question Paper Part 4

Q.23 What advantage does GMAW offer when welding stainless steel compared to other processes?

1. Low deposition rate
2. Limited joint access
3. Limited corrosion resistance
4. Precise control over heat input

Correct Option: 4

Q.24 A 0-120 V voltmeter has a guaranteed accuracy of 1 percent of full scale reading. The voltage measured by this instrument is 60 V. Calculate the limiting error in percent

1. 5%
2. 3%
3. 2%
4. 4%

Correct Option: 3

Q.25 What component or system is responsible for providing the initial magnetic field in an alternator’s rotor?

1. Prime mover (e.g., engine)
2. Exciter or excitation system
3. Voltage regulator
4. Cooling fan

Correct Option: 2

Q.26 What happens to the efficiency of a synchronous motor when it operates at a leading power factor compared to a lagging power factor?

1. Efficiency decreases at a leading power factor
2. Efficiency remains the same at both power factors
3. Efficiency increases at a leading power factor
4. Efficiency is not affected by the power factor

Correct Option: 3

NBCC Executive Electrical Question Paper Part 4