Science General · Physics

Energy and Electrical Devices

1,182 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

Multiple choice

A device that turns mechanical energy into electricity is called

  1. Transformer

  2. Turbine

  3. Dynamo

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A dynamo converts mechanical energy into electrical energy through electromagnetic induction - the principle used in generators and bicycle lights. Transformers change voltage levels, and turbines convert fluid/steam energy into mechanical energy.

Multiple choice

Capacity of doing work is called

  1. Energy

  2. Force

  3. Power

  4. Watt
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Energy is defined as the capacity to do work. The SI unit of energy is the Joule. Force causes acceleration (measured in Newtons). Power is the rate of doing work or using energy (Watts). The question tests the fundamental definition of energy.

Multiple choice

What is the general idea around which passage 2 revolves?

Answer the question based on the following passages.

Passage 1

            Wood was initially the sole heat energy provider. Later coal
            energized the western industry and finally came fuels like
            petroleum and natural gas to ignite the industrial sector. The
            triggered demand of energy has been due to boom in
(5)        modern luxuries like kitchen gadgets, air conditioners, heat
            pumps and the futuristic electric cars. So, to execute
            uninterrupted supply of energy, many coal fired and nuclear
            power plants have been set up. Even electric generators work
            with turbines to give hydroelectricity. Today electricity stands
(10)      distinctively as the most predominant energy provider. The
            oiling of kerosene lamps, hearth fires and cool iceboxes all are
            outdated. Now townships are planned near waterfalls so that
            easy energy can be obtained.
            Benjamin Franklin introduced the subject ‘electricity’ and Thomas
(15)      Edison brightened human life by inventing the first electric bulb.
            The electric charge was produced by the positive charge of
            protons and negative charge of electrons, both present in an atom.
            Their attraction to each other helps produce electrical charge.
            So the universally known principle of the attraction of opposites
(20)      helped produce electricity.

Passage 2

            Study of magnets acquaints us with the energy field which
            surrounds it, within which we feel the force of these magnets.
            A bar magnet pulls a piece of iron placed 2 cm away. If the
            potency is stronger it can make the iron almost dance to its
(5)        tune. Hence, if the attraction occurs, we can derive that the
            iron piece falls within the magnetic field. This comprehension
            of an energy field was difficult to relate in the past but for
            scientists today the concept stands clear that magnetic poles
            apply a force within a limit called its field. Even the molecules
(10)      of a liquid and air can be magnetized. Electric charge and
            magnetic charge both exert their force in a field. This electric
            field has both magnitude and direction represented by lines
            force or field lines, which begin on positive charges and
            terminate on negative charge. If electric energy could be
(15)      exploited for human use, can’t magnetic energy be not
            similarly used?

  1. It introduces the concept of charging a piece of iron.

  2. It relates magnetism to electrical charge and hints at similar use of the former.

  3. It discusses the technological use of magnetic field.

  4. It dwells on the possibility of utilization of magnets for deriving energy.

  5. It introduces the idea of magnetized air.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If electric energy could be exploited for human use, can't magnetic energy be not similarly used?

Multiple choice

What is the purpose of passage 1?

Answer the question based on the following passages.

Passage 1

            Wood was initially the sole heat energy provider. Later coal
            energized the western industry and finally came fuels like
            petroleum and natural gas to ignite the industrial sector. The
            triggered demand of energy has been due to boom in
(5)        modern luxuries like kitchen gadgets, air conditioners, heat
            pumps and the futuristic electric cars. So, to execute
            uninterrupted supply of energy, many coal fired and nuclear
            power plants have been set up. Even electric generators work
            with turbines to give hydroelectricity. Today electricity stands
(10)      distinctively as the most predominant energy provider. The
            oiling of kerosene lamps, hearth fires and cool iceboxes all are
            outdated. Now townships are planned near waterfalls so that
            easy energy can be obtained.
            Benjamin Franklin introduced the subject ‘electricity’ and Thomas
(15)      Edison brightened human life by inventing the first electric bulb.
            The electric charge was produced by the positive charge of
            protons and negative charge of electrons, both present in an atom.
            Their attraction to each other helps produce electrical charge.
            So the universally known principle of the attraction of opposites
(20)      helped produce electricity.

Passage 2

            Study of magnets acquaints us with the energy field which
            surrounds it, within which we feel the force of these magnets.
            A bar magnet pulls a piece of iron placed 2 cm away. If the
            potency is stronger it can make the iron almost dance to its
(5)        tune. Hence, if the attraction occurs, we can derive that the
            iron piece falls within the magnetic field. This comprehension
            of an energy field was difficult to relate in the past but for
            scientists today the concept stands clear that magnetic poles
            apply a force within a limit called its field. Even the molecules
(10)      of a liquid and air can be magnetized. Electric charge and
            magnetic charge both exert their force in a field. This electric
            field has both magnitude and direction represented by lines
            force or field lines, which begin on positive charges and
            terminate on negative charge. If electric energy could be
(15)      exploited for human use, can’t magnetic energy be not
            similarly used?

  1. To elucidate the importance of electricity and the sources that help in power generation.

  2. To explain how hydroelectricity generation facilitates life.

  3. To elaborate the production of electrical charge.

  4. To ponder on the need for energy sources and various means to meet the need.

  5. To compare the medieval life with wood as chief energy source to the modern life well-illuminated by electricity.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

(1) correctly sums up the passage's purpose.

Multiple choice

What is the common attribute in both the passages?

Answer the question based on the following passages.

Passage 1

            Wood was initially the sole heat energy provider. Later coal
            energized the western industry and finally came fuels like
            petroleum and natural gas to ignite the industrial sector. The
            triggered demand of energy has been due to boom in
(5)        modern luxuries like kitchen gadgets, air conditioners, heat
            pumps and the futuristic electric cars. So, to execute
            uninterrupted supply of energy, many coal fired and nuclear
            power plants have been set up. Even electric generators work
            with turbines to give hydroelectricity. Today electricity stands
(10)      distinctively as the most predominant energy provider. The
            oiling of kerosene lamps, hearth fires and cool iceboxes all are
            outdated. Now townships are planned near waterfalls so that
            easy energy can be obtained.
            Benjamin Franklin introduced the subject ‘electricity’ and Thomas
(15)      Edison brightened human life by inventing the first electric bulb.
            The electric charge was produced by the positive charge of
            protons and negative charge of electrons, both present in an atom.
            Their attraction to each other helps produce electrical charge.
            So the universally known principle of the attraction of opposites
(20)      helped produce electricity.

Passage 2

            Study of magnets acquaints us with the energy field which
            surrounds it, within which we feel the force of these magnets.
            A bar magnet pulls a piece of iron placed 2 cm away. If the
            potency is stronger it can make the iron almost dance to its
(5)        tune. Hence, if the attraction occurs, we can derive that the
            iron piece falls within the magnetic field. This comprehension
            of an energy field was difficult to relate in the past but for
            scientists today the concept stands clear that magnetic poles
            apply a force within a limit called its field. Even the molecules
(10)      of a liquid and air can be magnetized. Electric charge and
            magnetic charge both exert their force in a field. This electric
            field has both magnitude and direction represented by lines
            force or field lines, which begin on positive charges and
            terminate on negative charge. If electric energy could be
(15)      exploited for human use, can’t magnetic energy be not
            similarly used?

  1. Both indicate the latest developments in science.

  2. Both explore the evolution from electric energy to magnetic energy.

  3. Both forms of charge operate within a limited field.

  4. Both occur in nature and can be utilized naturally.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Passage 2, lines 10-11: “Electric charge and magnetic charge both exert their force in a field”.

Multiple choice

What is a major point of difference between passage 1 and passage 2?

Answer the question based on the following passages.

Passage 1

            Wood was initially the sole heat energy provider. Later coal
            energized the western industry and finally came fuels like
            petroleum and natural gas to ignite the industrial sector. The
            triggered demand of energy has been due to boom in
(5)        modern luxuries like kitchen gadgets, air conditioners, heat
            pumps and the futuristic electric cars. So, to execute
            uninterrupted supply of energy, many coal fired and nuclear
            power plants have been set up. Even electric generators work
            with turbines to give hydroelectricity. Today electricity stands
(10)      distinctively as the most predominant energy provider. The
            oiling of kerosene lamps, hearth fires and cool iceboxes all are
            outdated. Now townships are planned near waterfalls so that
            easy energy can be obtained.
            Benjamin Franklin introduced the subject ‘electricity’ and Thomas
(15)      Edison brightened human life by inventing the first electric bulb.
            The electric charge was produced by the positive charge of
            protons and negative charge of electrons, both present in an atom.
            Their attraction to each other helps produce electrical charge.
            So the universally known principle of the attraction of opposites
(20)      helped produce electricity.

Passage 2

            Study of magnets acquaints us with the energy field which
            surrounds it, within which we feel the force of these magnets.
            A bar magnet pulls a piece of iron placed 2 cm away. If the
            potency is stronger it can make the iron almost dance to its
(5)        tune. Hence, if the attraction occurs, we can derive that the
            iron piece falls within the magnetic field. This comprehension
            of an energy field was difficult to relate in the past but for
            scientists today the concept stands clear that magnetic poles
            apply a force within a limit called its field. Even the molecules
(10)      of a liquid and air can be magnetized. Electric charge and
            magnetic charge both exert their force in a field. This electric
            field has both magnitude and direction represented by lines
            force or field lines, which begin on positive charges and
            terminate on negative charge. If electric energy could be
(15)      exploited for human use, can’t magnetic energy be not
            similarly used?

  1. Passage 1 deals with a form of energy in use; passage 2 with a form of energy that can be used.

  2. Passage 1 is about electrical charge; passage 2 about mechanical charge.

  3. Passage 2 deals with attraction; passage 1 with repulsion.

  4. Passage 1 deals with predominance of electricity in daily life; passage 2 deals with uses of magnetism.

  5. Passage 1 deals with attraction of opposites; passage 2 with attraction of similarly charged objects.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If electric energy could be exploited for human use, can't magnetic energy be not similarly used?

Multiple choice

Which of the following sources was used to provide the power to Differential Engine?

  1. Steam

  2. Electricity

  3. Sun light

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Charles Babbage designed the Difference Engine and the Analytical Engine to be powered by steam. Since these were mechanical devices consisting of thousands of gears and wheels, they required a significant physical power source to operate. Electricity was not yet a practical power source for such machinery during Babbage's time in the 19th century.

Multiple choice

Consider the following statements:

(i) The energy losses from machines are mostly dissipated as sound energy. (ii) When current is supplied by a battery, the chemical energy is converted into electrical energy.

Which of the given statements is/are correct?

  1. Only (i)

  2. Only (ii)

  3. Both (i) and (ii)

  4. Neither (i) nor (ii)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement (i) is incorrect. The energy losses from machines are mostly dissipated as heat energy. Statement (ii) is correct. When current is supplied by a battery, the chemical energy stored in the battery converts into electrical energy.