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 physics communication system commonly used terms in electronic communication system elements of communication system electromagnetic waves and communication system

A carbon microphone is best used in a

  1. dynamo

  2. telephone

  3. transformer

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The telephone uses a carbon microphone . It is a transducer that converts the sound into elecrical audio signal.It consits of two metal plates seperated by granules of carbon-one plate is very thin and faces toward the speaking person,acting as a diaphragm.

Multiple choice physics types of energy law of conservation of energy the law of conservation of energy work, energy and machines

Does the Law of Conservation of energy apply to machines?

  1. No, as machines require a constant input of energy in order to work

  2. Yes, the energy required to maintain motion is balanced by the energy lost to friction

  3. No, as machines can create energy from motion

  4. Yes, but only to perpetual motion machines

  5. No, as the law would apply to only perpetual motion machines
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Machines require input work to be done on them, which increases the potential, or kinetic energy, or both of the system.

However this work is done on the machines by external systems that utilize their energies to convert them to work. 
So even though Law of Conservation of Energy holds for the entire system as a whole, it does not stand for the machines alone.

Multiple choice physics types of energy law of conservation of energy the law of conservation of energy work, energy and machines

Based on the Law of Energy Conservation, which of the following would best maintain a machine's ability to do work without input of additional energy?

  1. Decrease the amount of contact between component parts

  2. Increase contact between component parts

  3. use solar energy as the source

  4. use chemical energy as the source

  5. increase the number of parts in the machine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If we use solar energy or chemical energy it would mean input of additional energy , which is restricted in this case.

To increase the ability to do work of machine , we have to avoid the wastage of energy in the form of  heat produced , this heat is produced due to friction between component parts of machine .Friction between parts can be reduced by decreasing the amount of contact between parts .By doing that saved energy (which is not converted into heat) will be converted into work and this would best maintain the machine's ability.

Multiple choice physics sources of energy renewable and non-renewable resources renewable and non-renewable sources of energy production of electricity from solar energy biogas environmental use of microorganism microbes in waste treatment and biogas

In a wind mill the electric energy is converted into mechanical energy.         

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B.
Windmills, like waterwheels, were among the original prime movers that replaced animal muscle as a source of power. They were used for centuries in various parts of the world, converting the energy of the wind into mechanical energy for grinding grain, pumping water, and draining lowland areas.
Kinetic energy of the wind is transformed into mechanical energy of the turning windmill. This can be used to turn a generator to generate electricity. The original energy to cause the wind to blow came from the sun. Uneven heating of the earth's surface causes wind.
Hence, the statement is false.

Multiple choice physics towards green energy renewable and non-renewable resources renewable and non-renewable sources of energy production of electricity from solar energy

In a thermoelectric station the energy Which changes into electric energy is :

  1. chemical energy

  2. potential energy

  3. nuclear energy

  4. heat energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Answer is D.

The heat produced by either steam or coal is converted in to electrical energy. Thus, in a thermal power station, heat energy is converted to electrical energy.

Multiple choice physics some natural phenomena how lightning occurs? the story of lightning advanced of lightning

A lightning rocket is a device used to control 

  1. time and location of a lighting strike.

  2. fuel and location of a lighting strike.

  3. the lighting of the strom

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A lightening rocket is a rocket device, about the size of a man, that trails behind a conductor, such as fine copper wire. It is therefore, a conducting lightening rod which is grounded and positioned along side the launch tube in communication with the conductive path to thereby control time and location of a lightening strike from the thundercloud.

Multiple choice wireless connections parts of computer physics

Which technology is more reliable?

  1. Mechanical

  2. Electro-Mechanical

  3. Electronic

  4. For reliability it does not matter. So all of above are reliable
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For reliability it does not matter. So all of above are technology is more reliable.

Mechanical Technology. Nearly every product includes mechanical components that must be created by a mechanical designer. ... The mechanical designer of today requires knowledge in many areas including mechanical drafting, computer-aided drafting and design, machine shop, robotics and machine components.

A mechanical computer is built from mechanical components such as levers and gears, rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays.

Computer Electronics Technology is an associate degree program that prepares you for a technical career in the computer field. You will learn to operate, install, configure, upgrade and maintain microcomputers, peripheral devices and network hardware.