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).
Which is proportional to the torque in D.C motor?
The voltage of domestic supply is 240 V. This number represents:
What is the starting current of an A.C 3 phase induction motor?
In a three-phase, 4-wire system, what is the approximate typical voltage between any two phases if the line-to-neutral voltage is 230 V?
Which insulation class is typically used in motors that operate continuously at temperatures up to $180^{\circ}\text{C}$?
Which type of fire extinguisher is used for fire on electrical equipment?
Calculate the total power of the circuit in which two lamps rated at 200W/240V are connected in series across 240V supply?
What is the change in resistance of the conductor if its diameter is doubled?
Heating element of an oven draws 10 Amp current from 240 V mains. How many units of energy will be consumed in one hour and 15 minute?
Which motor is preferred for Cranes and hoists?
A power system has a total connected load of 10 KW and a maximum demand of 5 kW. What will be the demand factor?
Calculate the apparent power in KVA of 3 Phase 415 V, 50 Hz star system, if the line current is 16 Amp at 0.8 power factor.
Four heaters of rating 2 KW, 230 V each are available. How will you connect them for maximum heat?
Buchholz relay operates when there is:
A shunt generator delivers 50 A at 100 V. Find the generated voltage if shunt field resistance and armature resistance are 50 Ω and 0.1 Ω respectively.
The lead acid cell should not be discharged below:
How to obtain opposite polarity in adjacent poles of a 4 pole DC motor?
Calculate the current in secondary side of a transformer with primary turns of 400 and secondary turns of 100, if 20A current is flowing through primary.
Calculate the percentage slip in a 3 phase induction motor having 6 poles with a frequency of 50 Hertz rotating with actual speed of 960 rpm?
What is the function of timer in automatic star delta starter?
How can power factor be improved?
What is the ripple frequency ($F$) of full wave rectifier, if $F_{in}$ is input frequency?
Calculate the impedance of the given circuit if $R = 5\;\Omega$, $X_L = 36\;\Omega$, and $X_C = 24\;\Omega$ connected to a 240 V AC supply.
In a 3 phase system, if the active power is 4 kW and the apparent power is 5 kVA, calculate the reactive power?
What is the relation between the line current ($I_L$) and phase current ($I_P$) in delta connected system?