Science General · Physics
Energy and Electrical Devices
1,193 Questions
Energy and electrical devices focus on energy conversion, household electrical appliances, batteries, and electric vehicle technology. These principles are essential components of general science syllabi across major competitive examinations. Review these practice questions to strengthen understanding of electrical energy applications and devices.
Energy conversionHousehold electrical appliancesBatteries and cellsElectric vehicles
Energy and Electrical Devices Questions
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The Clark cell
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An electrochemical cell
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Galvanic cell
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Commodity cells
A
Correct answer
Explanation
The Clark cell, is a wet-chemical cell that produces a highly stable voltage usable as a laboratory standard.It uses a zinc, or zinc amalgam, anode and a mercury cathode in a saturated aqueous solution of zinc sulfate, with a paste of mercurous sulfate as depolarizer.
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Fan
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Television
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Computer
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Refrigerator
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Inverter
E
Correct answer
Explanation
In the group, inverter is the only electricity producer. So, it is the correct answer.
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A roller coaster on the top of a hill track.
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A rocket ready for takeoff.
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Boiling of liquid nitrogen.
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A lady resting on bed.
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A snowball on top of a snowy mountain.
C
Correct answer
Explanation
Yes, it is an example of kinetic energy.
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Compact fluorescent lamp
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A blue coloured bulb
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Halogen lamp
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LED bulb
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None of these
D
Correct answer
Explanation
Yes, it is correct. LED gives more light, but does not produce heat. Hence, wastage of electricty is nill or very little.
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Major circuit breaker
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Micro circuit breaker
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Miniature circuit breaker
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Major circuit board
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Miniature circuit board
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Electric iron
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Water heater
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Geyser
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Juicer
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Toaster
D
Correct answer
Explanation
Juicer works on magnetic effect of electric current and not its heating effect, like the rest of the given devices.
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storage batteries
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fans
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TVs
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bicycles
A
Correct answer
Explanation
Lead is a key component in lead-acid storage batteries, used in cars and backup power systems. Lead plates and sulfuric acid create the electrochemical reaction. Lead is too heavy and toxic for use in fans, TVs, or bicycles.
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electric energy into sound energy
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electric energy into light energy
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heat energy into mechanical energy
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heat energy into electric energy
B
Correct answer
Explanation
An electric bulb converts electrical energy into light energy (and some heat energy). This is the fundamental principle of how incandescent and LED bulbs work - they transform electricity into visible light. Sound energy production would be a speaker, while mechanical energy conversion relates to motors and generators.
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electric sources
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pneumatic sources
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both (1) and (2)
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none of these
C
Correct answer
Explanation
Gyroscopic instruments in aircraft require power to maintain their high-speed rotation. Electric systems use vacuum pumps or electric motors, while pneumatic systems use engine-driven vacuum pumps. Modern aircraft typically have both power sources available for redundancy and在不同飞行条件下的灵活性。
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Torches
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Door bells
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Generators
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Loud speakers
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eddy current loss
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hysteresis loss
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copper loss
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friction loss
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brushes
C
Correct answer
Explanation
Yes, it's the correct choice.
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Simple and rugged construction
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Good power factor
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High efficiency
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Absence of commutator
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All of the above
E
Correct answer
Explanation
All the above options are true.
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dynamo
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rotar
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electric motor
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microphone
C
Correct answer
Explanation
An electric motor converts electrical energy into mechanical energy through electromagnetic principles. When current flows through coils in a magnetic field, it creates rotational motion. This is the reverse of a generator's function.
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microphone
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electric heater
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photo electric cell
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electric motor
B
Correct answer
Explanation
An electric heater contains a heating element (resistor) that converts electrical energy into heat energy through Joule heating. Microphones convert sound energy to electrical energy, photo electric cells convert light energy to electrical energy, and electric motors convert electrical energy to mechanical energy.
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Amplifier
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Motor
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Dynamo
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Photo electric cell
D
Correct answer
Explanation
A photo electric cell works on the photoelectric effect - when light strikes certain materials, electrons are ejected, creating electrical energy. Amplifiers increase signal strength, motors convert electricity to motion, and dynamos convert mechanical energy to electrical energy.