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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
- Thermal relay
- Distance relay
- Differential relay
- None of these
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Explanation
Distance relays detect faults by measuring the impedance between the relay location and the fault.
If the impedance falls below a set threshold, indicating a nearby fault, the relay operates to isolate the affected section.
- Store electrical energy
- Generate electricity
- Detect faults
- None of these
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Explanation
Protective relays monitor electrical parameters and identify abnormal conditions such as overcurrent or short circuits.
They trigger circuit breakers to isolate faulty sections, preventing damage to equipment and ensuring system safety.
- Field winding
- Commutator
- Armature
- None of these
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Explanation
The armature of a DC machine carries current and interacts with the magnetic field to produce torque.
This torque converts electrical energy supplied to the machine into mechanical rotational energy.
- To amplify the signal
- To convert digital to analog
- To impress information
- None of these
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Explanation
A modulator encodes the information signal onto a carrier wave for effective transmission over a communication channel.
This allows signals to travel long distances without significant loss or interference.
- Inductor
- Transformer
- Circuit breaker
- None of these
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Explanation
Circuit breakers automatically interrupt the flow of current when it exceeds a safe limit, protecting equipment and wiring.
They are essential safety devices in power distribution systems to prevent damage from overcurrent or short circuits.
- 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.
