Master official Physical Research Laboratory (PRL), Ahmedabad Technician 'B' (Electrician) recruitment examination questions across Basic Electrical Principles & Circuit Laws, Magnetism & Inductance, AC Fundamentals & Polyphase Circuits, Substation Transformers, High-Precision Servo Drives & Stepper Motors for Astronomical Telescopes, Cryocooler Compressor Motor Drives, Laboratory Online UPS & VRLA Battery Banks, Dedicated Low-Noise Clean Instrumentation Earthing (<0.5Ω), Power Cabling & Cleanroom Electrical Distribution, Electrical Measuring Instruments, and Laboratory Safety Standards.
Marking pattern: +1.00 / +3.00 positive, -0.33 / -1.00 (1/3rd) negative marking (Official DOS / ISRO / PRL Written Test / CBT Scheme).
What is the approximate efficiency of a normal thermal power plant?
The capacitance of a capacitor is not influenced by:
Calculate the heat generated in a electric heater of 2000 watt and 240 volt if it worked for 5 minutes?
Calculate the voltage regulation in percentage of the transformer if the no load voltage is 240 volt and full load voltage is 220 volt?
A 3-phase, 400 V, 50 Hz, delta connected induction motor draws a line current of 150 A with a power factor of 0.85 and is delivering an output of 100 HP. Calculate its efficiency.
A coil of copper wire 200 m long and cross sectional area of 0.8 $\text{mm}^2$ has a resistivity of $0.02\;\mu\Omega\cdot\text{m}$ at normal working temperature. Calculate the resistance of the coil.
What will be the output DC voltage in half wave rectifier, if the input AC voltage is 24 volt?
The value of binary number 110111 in decimal system is:
Burden of instrument transformer is given in:
Turns of the coil of the moving iron type voltmeter are:
While measuring power in single phase load having power factor of 0.8 lagging using CT ratio 100:5 and PT ratio of 1100:110 V, the wattmeter reading is 100 W. Then power consumed by the load will be:
Under dry condition, the minimum resistance offered by human body is about:
ELCB is not normally manufactured for the earth fault current of:
If a 60 watt bulb and a 40 watt bulb are connected in series across a 250 Volt supply, which bulb will be brighter?
Calculate the power factor of a coil having resistance of 24 $\Omega$, drawing current of 5 A, at 240 V/50 Hz AC supply.
An induction motor works with:
Which is the correct sequence operation of contactors for operating automatic star delta starter?
The frequency of EMF produced in 4-pole, 1800 RPM alternator is:
In transformer, tapping are provided in:
The watt meter reading of a transformer in open circuit is 900 W and in short circuit at full load is 1600 W. What will be the iron loss at half load?
Which one of the following type of DC motor is best suited for electric traction?
What is the name of the component marked as 'X' in the block diagram of AC drive?
What should be done to disconnect an ammeter from the secondary terminals of Current Transformer (CT)?
Three capacitors, each with a breakdown voltage of 500 V, are connected in parallel. What is the breakdown voltage rating of the combination?
To avoid electrical hazards due to static electricity on metal-bodied machinery, which of the following should be used?