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Past Questions — 2026
A computer program that converts an entire program into machine language is called:
A)
Interpreter
B)
Simulator
C)
Compiler
D)
Programmer
A compiler translates the entire source program into machine language at once, producing object/executable code. An interpreter translates and executes the program line by line, so option (a) is incorrect. A simulator imitates the working of another system, so option (b) is incorrect. A programmer is a person who writes programs, so option (d) is incorrect.
Which of the following is an example of a GUI Operating System?
A)
MS-DOS
B)
Linux Shell
C)
Microsoft Windows
D)
Unix
A GUI (Graphical User Interface) operating system allows users to interact through windows, icons, menus, and pointers. Microsoft Windows is a standard example of a GUI operating system. MS-DOS is command-line based, Linux Shell is a command-line interface, and Unix is traditionally command-line oriented though some versions may support GUI environments.
Which register holds the address of active memory location?
A)
Control Address Register
B)
Memory Address Register
C)
Arithmetic Register
D)
Index Address Register
The Memory Address Register (MAR) stores the address of the memory location that is currently being accessed by the CPU, whether for reading or writing. Hence it holds the address of the active memory location.
Why others are incorrect:
(a) Control Address Register is related to control operations, not main memory location addressing.
(c) Arithmetic Register is used for arithmetic data/operations, not for storing memory addresses.
(d) Index Address Register is used for indexed addressing and address modification, but it does not specifically hold the currently active memory location address.
Operating system, editors, and debuggers comes under:
A)
System Software
B)
Application Software
C)
Utilities
D)
None of the above
Operating systems, editors, and debuggers are all examples of system software because they help run, control, and support the computer system and application programs. Application software is meant for end-user tasks like word processing or accounting. Utilities are a subset of system support tools, but the broader and correct category covering operating systems, editors, and debuggers together is system software.
In MS-word, ‘Ctrl+Home’ is used to:
A)
Move the cursor to the beginning of Document
B)
Move the cursor to the beginning of Line
C)
Move the cursor to the beginning of Paragraph
D)
None of the above
In MS Word, the shortcut Ctrl + Home moves the insertion point/cursor directly to the start of the entire document. Therefore, option (a) is correct. Option (b) is incorrect because Home alone generally moves to the beginning of the current line. Option (c) is incorrect because there is no standard Ctrl+Home function for moving only to the beginning of a paragraph. Hence, (d) is also incorrect.
What does the term “bit” stand for?
A)
Binary Digit
B)
Binary Information Test
C)
Basic Information Transfer
D)
Basic Input Terminal
A bit is the smallest unit of data in computing and the word 'bit' is short for 'binary digit'. It can have only two values: 0 or 1. Hence option (a) is correct. The other options are incorrect because 'Binary Information Test', 'Basic Information Transfer', and 'Basic Input Terminal' are not the expansion of the term bit.
An Induction motor can be said to be analogous to:
A)
Transformer
B)
Synchronous motor
C)
Universal motor
D)
Stepper motor
An induction motor is analogous to a transformer because both work on the principle of electromagnetic induction. In a transformer, the primary winding induces voltage in the secondary winding; in an induction motor, the stator induces emf in the rotor. The main difference is that in a motor the secondary (rotor) is rotating and mechanically loaded, while in a transformer it is stationary. The other options are not analogous: a synchronous motor works at synchronous speed, a universal motor is a series AC/DC motor, and a stepper motor moves in discrete steps.
The rotor of a 3 phase induction motor always runs at:
A)
Synchronous speed
B)
Less than synchronous speed
C)
More than synchronous speed
D)
None of these
In a 3-phase induction motor, the rotor must run slightly below synchronous speed so that there is relative motion between the rotating magnetic field and the rotor conductors. This relative motion induces rotor EMF and current, which produce torque. If the rotor reached synchronous speed, no EMF would be induced, so torque would become zero. Hence, the rotor always runs at less than synchronous speed.
A chopper may be thought as:
A)
Inverter with DC input
B)
DC equivalent of an AC transformer
C)
Diode rectifier
D)
DC equivalent of an induction motor
A chopper is a DC-DC converter used to obtain a variable DC output from a fixed DC input. Because a transformer changes AC voltage levels, a chopper is commonly described as the DC equivalent of an AC transformer. Option (a) is incorrect because an inverter converts DC to AC, not DC to variable DC. Option (c) is incorrect because a diode rectifier converts AC to DC. Option (d) is unrelated.
Which tool is essential for checking continuity in an electric iron or heater?
A)
Screwdriver
B)
Multimeter
C)
Pliers
D)
Hammer
A multimeter is used to test electrical continuity by measuring resistance or using its continuity function. In an electric iron or heater, it helps check whether the heating element circuit is complete or broken. Screwdriver, pliers, and hammer are mechanical tools and cannot check electrical continuity.
The most commonly used semiconductor material is:
A)
Silicon
B)
Germanium
C)
Mixture of Silicon and Germanium
D)
None of the above
Silicon is the most commonly used semiconductor material because it is abundant, inexpensive, thermally stable, and has suitable electrical properties for making diodes, transistors, and integrated circuits. Germanium was used earlier, but silicon replaced it in most applications due to better temperature performance and lower leakage current. A mixture of silicon and germanium is used only in special devices, not as the most common material.
What is the major drawback of wind energy?
A)
High pollution
B)
It is not renewable
C)
Intermittent and variable nature
D)
Low energy efficiency
Wind energy’s main limitation is that it depends on wind availability, which is not constant. Since wind speed changes with weather and time, power generation is intermittent and variable. Option (a) is incorrect because wind energy is clean and has very low pollution during operation. Option (b) is incorrect because wind is a renewable source. Option (d) is not the major drawback; while efficiency and capacity factor matter, the key issue is the unpredictability of supply.
Core of a Transformer is laminated to:
A)
minimize hysteresis loss
B)
minimize Eddy current loss
C)
minimize copper loss
D)
minimize both hysteresis and eddy current loss
The transformer core is laminated into thin insulated sheets to break the path of circulating currents induced in the core. This reduces eddy currents, thereby minimizing eddy current loss. Hysteresis loss depends on the magnetic properties of the core material and is reduced by using suitable materials like silicon steel, not by lamination. Copper loss occurs in the windings due to their resistance, so lamination does not affect it.
What is the standard value of solar constant?
A)
1 kW/m2
B)
1.367 kW/m 2
C)
1.5kW/m2
D)
5 kW/m2
The solar constant is the amount of solar radiation received per unit area at the outer edge of Earth’s atmosphere on a surface normal to the Sun’s rays at mean Earth–Sun distance. Its standard accepted value is about 1367 W/m², which is 1.367 kW/m². The other options are not the standard solar constant.
Which of the following energy has the greatest potential among all the sources of renewable energy?
A)
Solar energy
B)
Wind Energy
C)
Thermal energy
D)
Hydro-electrical energy
Solar energy has the greatest potential among renewable energy sources because the sun provides an immense, continuous supply of energy to the Earth. Compared with wind, hydro, and geothermal/thermal sources, solar is far more abundant and widely available. Wind and hydro depend on specific geographic and climatic conditions, while solar energy is available almost everywhere.
A diac has_________ terminals.
A)
two
B)
three
C)
four
D)
five
A DIAC (Diode for AC) is a two-terminal bidirectional trigger device. It conducts after its breakover voltage is reached in either polarity. Therefore, it has only two terminals. Options (b), (c), and (d) are incorrect because three terminals are associated with devices like TRIACs, not DIACs.
A Photovoltaic cell converts sunlight directly into:
A)
Heat energy
B)
Mechanical energy
C)
Electrical energy
D)
Chemical energy
A photovoltaic (PV) cell works on the photovoltaic effect, by which sunlight is directly converted into electrical energy. It does not produce heat as the main output, nor mechanical or chemical energy. Therefore, the correct option is (c) Electrical energy.
Solar PV system are broadly classified into:
A)
1
B)
2
C)
3
D)
4
Solar PV systems are broadly classified into 2 types: (1) stand-alone (off-grid) systems and (2) grid-connected systems. Sometimes hybrid systems are discussed as a combination, but the broad basic classification is into two main categories. Hence, option (b) is correct.
Function of a Breather in a Transformer is:
A)
to absorb the moisture of air.
B)
to pass cold air to the Transformer.
C)
to insulate the core.
D)
for cooling the temperature.
A breather in an oil-immersed transformer contains silica gel and is fitted to the conservator tank. When the transformer oil expands and contracts, air enters and leaves through the breather. Its function is to remove moisture from the incoming air so that damp air does not contaminate the transformer oil. Therefore, option (a) is correct. Options (b), (c), and (d) are incorrect because the breather is neither used to supply cold air, nor to insulate the core, nor primarily for cooling.
AC voltage controllers convert:
A)
Fixed ac to fixed dc
B)
Variable ac to variable dc
C)
Fixed ac to variable ac
D)
Variable ac to fixed ac
AC voltage controllers are power electronic converters used to control the RMS value of an AC supply without changing its frequency. Thus, they take a fixed AC input and provide a variable AC output. Option (a) describes an AC to DC converter (rectifier), option (b) refers to a chopper/inverter-related conversion but not AC voltage controller, and option (d) is not a standard power conversion category.
The Solar Cell efficiency is about:
A)
15%
B)
25%
C)
48%
D)
63%
A typical commercial solar cell has an efficiency of about 15% to 20%. Among the given options, 15% is the closest and standard exam answer. 25%, 48%, and 63% are much higher than usual efficiency values for ordinary solar cells.
Which instrument is used to measure direct solar radiation?
A)
Pyranometer
B)
Sunshine Recorder
C)
Pyrheliometer
D)
Anemometer
Direct solar radiation (beam radiation) is measured using a pyrheliometer. A pyranometer measures total or global solar radiation on a surface, a sunshine recorder measures duration of bright sunshine, and an anemometer measures wind speed.
The Wind speed is measured using an instrument called:
A)
Hydrometer
B)
Manometer
C)
Anemometer
D)
Wind Vane
Wind speed is measured by an anemometer. A wind vane shows wind direction, not speed. A hydrometer measures the specific gravity of liquids, and a manometer measures pressure difference.
A single phase motor has:
A)
Zero starting torque
B)
Low starting torque
C)
High starting torque
D)
None of the above
A single-phase induction motor is not self-starting. At standstill, the alternating field produced by the single-phase supply can be resolved into two equal and opposite rotating fields, giving no net starting torque. Hence its starting torque is zero. Therefore, option (a) is correct. Option (b) is incorrect because the starting torque is not merely low; it is zero without any starting aid. Option (c) applies to some special motor types or starting arrangements, not a plain single-phase motor.
Most of the Solar Cells are made of:
A)
Magnesium
B)
Iron
C)
Radium
D)
Silicon
Most solar cells are made of silicon because it is a semiconductor, which can efficiently convert sunlight into electricity through the photovoltaic effect. Magnesium, iron, and radium are not commonly used as the main material for solar cells.