Find real questions from previous competitive exam papers with answers and solutions.
Leave the keyword blank to browse saved questions for your selected exam, newest papers first. Add a keyword, year or topic to narrow the results.
Browse complete papersWhich generator in wind turbines uses slip rings and a partially rated converter for variable-speed operation?
squirrel cage induction generator
doubly-fed induction generator
permanent magnet synchronous generator
brushless DC generator
Correct answer
squirrel cage induction generator
Three identical capacitors are connected in parallel. If the total charge stored in the system is Q, what is the charge on each individual capacitor?
Q/3
3Q
Q/9
Q
Correct answer
Q/3
Which strategy reduces electricity charges under a power factor tariff system for a manufacturing plant with predominantly inductive loads?
Operating all equipment at full load constantly
Increasing lighting hours during low demand periods
Installing capacitors to improve the power factor of inductive loads
Switching to higher voltage transformers without changing load characteristics
Correct answer
Operating all equipment at full load constantly
Field failure protection in an alternator is provided to detect:
Variation in illumination intensity inside generator control panels
Reduction in paint thickness of alternator outer protective enclosure
Loss of excitation current in the synchronous generator field winding
Change in colour of lubricating oil storage tank surface coating
Correct answer
Variation in illumination intensity inside generator control panels
Which statement correctly explains the principle of direct resistance heating?
Heat is generated by the resistance of the material through which the current flows, and it is applied directly to the heating element
The heating element works by electromagnetic induction
Heat is produced through the conversion of mechanical energy into heat
The process is based on the principle of convective heat transfer
Correct answer
Heat is generated by the resistance of the material through which the current flows, and it is applied directly to the heating element
Which consideration is important while deciding the capacity of a power station?
Expected maximum electrical demand and future load growth requirements
Number of ceiling fans installed inside administrative office sections
Shape of fencing structure surrounding the generating station premises
Type of paint applied on generating station external building surfaces
Correct answer
Expected maximum electrical demand and future load growth requirements
Which of the following points are True regarding the effect of short-time duty on the size and cost of electric motors?
i) Short-time duty allows use of higher rated motors for short durations.
ii) Motors used for short-time duty are generally smaller for the same load.
iii) Short-time duty increases the need for oversized enclosures.
iv) Cost per kW is lower for motors used in short-time duty.
(i), (iii), and (iv) only
(i) and (iii) only
(ii), (iii), and (iv) only
(i), (ii), and (iv) only
Correct answer
(i), (iii), and (iv) only
An oscilloscope displays a measured rise time of 10 ns when observing a fast pulse. If the oscilloscope itself has a specified rise time of 6 ns, then what is the approximate actual rise time of the signal being measured?
4 ns
6 ns
8 ns
12 ns
Correct answer
4 ns
In a single-phase parallel RL circuit connected to a single phase AC supply, which of the following is correct?
Current leads voltage
Power factor is leading
Current lags voltage
Power factor is unity
Correct answer
Current leads voltage
Concentrating solar technology is a type of solar power technology which:
uses sunlight energy to directly rotate turbines without a heat conversion stage
produces heat from sunlight without using mirrors or optical concentration
directly converts sunlight into electricity using photovoltaic (PV) panels
uses mirrors to focus sunlight, generating heat that drives turbines to produce electricity
Correct answer
uses sunlight energy to directly rotate turbines without a heat conversion stage