ELECTRICAL ENGINEERING PAST PAPERS AND SYLABUS
Electrician
چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
- Generate electrical power
- Increase voltage
- Convert AC to DC
- Reduce voltage
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Explanation
A step-down transformer lowers high transmission voltage to safer levels suitable for consumer use.
This reduction minimizes energy losses and ensures safe operation of electrical appliances.
- Continuous signal consumption
- Lower power
- Higher noise immunity
- None of these
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Explanation
Digital signals are less affected by noise because they use discrete levels (0s and 1s).
Errors introduced by noise can be detected and corrected more easily in digital systems.
- Plant
- Sensor
- Controller
- None of these
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Explanation
The controller receives the error signal (difference between desired and actual output) and processes it using a control law.
It then generates the control action needed to drive the system toward the desired output.
- Capacitor
- Diode
- MOSFET
- None of these
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Explanation
MOSFETs are widely used as electronic switches in DC circuits due to their fast switching speed and high efficiency.
They require very little gate current, making them ideal for power electronics applications.
- Chemical → Electrical
- Mechanical → Electrical
- Heat → Mechanical → Electrical
- None of these
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Explanation
In a thermal power plant, heat energy from fuel is first converted into mechanical energy by rotating the turbine.
The turbine then drives a generator, converting mechanical energy into electrical energy.
- Active power
- Reactive power
- Apparent power
- None of these
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Explanation
Apparent power is the product of RMS voltage and RMS current, measured in volt-amperes (VA).
It represents the total power supplied in an AC circuit, including both real and reactive components.
- P = V × I
- P = V × I²
- P = V² × I
- None of these
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Explanation
Electrical power in a DC circuit is the product of voltage and current.
It represents the rate at which electrical energy is converted into other forms.
- Temperature of the inductor
- Product of the instantaneous current and rate of charge of current
- Square of the rate of charge of current
- None of these
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Explanation
Instantaneous power in an inductor is given by p = vi = Li di/dt, so it depends on current and its rate of change.
This shows energy is stored in (or released from) the magnetic field, not dissipated as heat.
- b = l + n - 4
- b = l + n - 2
- b = l + n - 1
- None of these
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Explanation
The fundamental theorem of network topology states that the number of branches equals the sum of independent loops and nodes minus one.
This relation is essential for applying Kirchhoff’s laws in electrical network analysis.
- 3.5 to 5
- 1.5 to 2
- 2.5 to 3
- None of above
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Explanation
Large induction motors are designed with low slip to achieve high efficiency and better speed regulation.
From no-load to full-load, their slip typically increases only slightly, remaining around 1.5–2%.
