10+ VE Commercial Vehicles Interview Questions and Answers

The conductors will attract each other due to the magnetic field produced by the current flowing through them.

• The conductors will experience a force of attraction between them

• This is due to the magnetic field produced by the current flowing through the conductors

• The direction of the current flow will determine the direction of the force

The two transistor model of a Silicon Controlled Rectifier consists of an NPN and PNP transistor connected in a feedback loop.

• The NPN transistor is connected in series with the PNP transistor, forming a regenerative feedback loop.

• When a gate pulse is applied, it triggers the NPN transistor to turn on, which in turn triggers the PNP transistor to turn on.

• This regenerative process continues until the SCR is in forward conductive state.

• The gate pulse must be of sufficient amplit...read more

Transmission voltage is kept high to reduce power loss over long distances.

• Higher voltage reduces current, which in turn reduces power loss in transmission lines.

• High voltage allows for efficient long-distance transmission without significant power loss.

• Step-up transformers increase voltage for transmission, while step-down transformers decrease voltage for distribution.

• Power loss is proportional to the square of the current, so reducing current by increasing voltage helps mi...read more

The source impedance for maximum power transfer in AC circuits should be equal to the complex conjugate of the load impedance.

• Source impedance should be equal to the complex conjugate of the load impedance for maximum power transfer.

• This condition ensures that the maximum power is transferred from the source to the load.

• In AC circuits, the source impedance should match the load impedance to achieve maximum power transfer.

• The formula for maximum power transfer is Zs = Zl* wher...read more

Complex conjugate is needed to maximize power transfer by ensuring the impedance matching between the source and load.

• Complex conjugate helps in achieving impedance matching between source and load

• Impedance matching minimizes reflections and maximizes power transfer

• By taking the complex conjugate, the real part of the impedance is matched while the imaginary part cancels out

In an RLC circuit, the power quality across an inductor is reactive power.

• The power quality across an inductor in an RLC circuit is reactive power, which means it does not result in actual work being done but rather stores and releases energy in the form of magnetic fields.

• The reactive power in an inductor leads to a phase shift between voltage and current, with the current lagging behind the voltage in an inductive circuit.

• The power factor in an inductive circuit is less tha...read more

A transistor configuration with high input impedance and low output impedance is called a buffer.

• Buffers are used to isolate two circuits with different impedance levels.

• Common emitter or common collector configurations are often used as buffers.

• Buffers help prevent loading effects and signal distortion in electronic circuits.

Single phase induction motors are not self-starting due to the absence of a rotating magnetic field.

• Single phase induction motors lack a rotating magnetic field, which is necessary for self-starting.

• The starting torque in single phase motors is zero, making it impossible for them to start on their own.

• Additional starting mechanisms such as capacitors or shaded poles are required to create the necessary rotating magnetic field for starting.

• Once the motor reaches a certain spee...read more

DC series motor is preferred for traction applications due to its high starting torque and speed control capabilities.

• DC series motor provides high starting torque, making it suitable for traction applications where high torque is required to start moving heavy loads.

• DC series motor offers good speed control capabilities, allowing for smooth acceleration and deceleration in traction applications.

• DC series motor is simple in design and easy to maintain, making it cost-effectiv...read more

Yes, a lagging zero power factor device can deliver active power.

• A lagging zero power factor device can still deliver active power because it consumes both real and reactive power.

• The power factor is a measure of how effectively electrical power is being converted into useful work output.

• Even though the power factor may be lagging (less than 1), the device can still deliver active power to the load.

• Examples of devices with lagging zero power factor include induction motors an...read more

The basic electrical power equation is P = VI, where P is power, V is voltage, and I is current.

• The basic electrical power equation is P = VI

• Power (P) is measured in watts (W)

• Voltage (V) is measured in volts (V)

• Current (I) is measured in amperes (A)

• The equation shows the relationship between power, voltage, and current

Common emitter is called an inverter because it produces an output that is the opposite of the input signal.

• In a common emitter configuration, the output signal is 180 degrees out of phase with the input signal.

• The common emitter amplifier produces a phase shift of 180 degrees, effectively inverting the input signal.

• This inversion property is why the common emitter amplifier is also known as an inverter.

25 KV is preferred for railway traction due to its higher efficiency, reduced power loss, and ability to support longer distances.

• 25 KV allows for higher speeds and heavier loads compared to lower voltages like 1.5 KV or 3 KV

• It reduces power loss during transmission, leading to higher efficiency and cost savings

• Higher voltage enables longer distances between substations, reducing infrastructure costs

• 25 KV is a standard voltage used in many countries for railway electrificatio...read more

Yes, active power can be transferred using it.

• Yes, active power can be transferred using electrical systems like transformers and transmission lines.

• Active power transfer is essential for the functioning of electrical grids and power distribution networks.

• Examples include transferring power from a power plant to homes and businesses.

• Active power transfer is measured in watts (W) or kilowatts (kW).

No, an opAmp cannot be used as a computer.

• OpAmps are analog devices used for amplifying signals, not for digital computation.

• OpAmps lack the necessary components such as memory, processing units, and input/output interfaces to function as a computer.

• Computers require complex digital circuits and software to perform tasks, which opAmps are not designed for.

KCL and KVL have limitations in complex circuits and non-linear components.

• KCL assumes all currents entering a node must equal all currents leaving, which may not hold true in complex circuits.

• KVL assumes the sum of voltage drops in a closed loop is zero, which may not be accurate in circuits with non-linear components.

• Both laws are based on ideal conditions and may not be applicable in real-world scenarios.

• KCL and KVL do not account for parasitic elements like capacitance an...read more

Barkhausen Criteria is used in determining the conditions for the onset of magnetic domain wall motion in ferromagnetic materials.

• Used in understanding the behavior of magnetic domains in ferromagnetic materials

• Helps in predicting the conditions for the initiation of magnetic domain wall motion

• Important in the study of magnetic hysteresis and magnetic materials