Science General ยท 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

Cars with hybrid and electric motors ____

  1. create less air pollution than conventional cars

  2. use solar panels for power

  3. use more fuel than conventional cars

  4. are no longer produced
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hybrid and electric vehicles are designed to be more energy-efficient and produce significantly fewer tailpipe emissions compared to traditional internal combustion engines.

Multiple choice

Which of these have some utility?

  1. Water

  2. Electricity

  3. Vegetable

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Utility is the quality of being useful or satisfying a need. Water, electricity, and vegetables all provide utility to humans.

Multiple choice

Can you create or destroy energy?

  1. No

  2. Yes

  3. Only if you are really strong

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

Energy cannot be created or destroyed according to the law of conservation of energy. It can only be transformed or transferred.

Multiple choice

Which of the following has the most potential energy?

  1. A car at the top of a hill

  2. A person at the top of a hill

  3. A car speeding down the hill

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

Gravitational potential energy depends on mass and height (PE = m * g * h). A car has much more mass than a person, so a car at the top of a hill has more potential energy than a person at the same height.

Multiple choice

The lighting of a candle in a menorah/kinara creates which type of energy transformation?

  1. chemical-potential to thermal & radiant

  2. mechanical to thermal & radiant

  3. thermal to radiant & chemical-potential

  4. radiant to thermal & mechanical
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The wax in a candle contains chemical potential energy stored in its molecular bonds. When burned, this energy is released as thermal energy (heat) and radiant energy (light).

Multiple choice

what is mechanical energy

  1. the energy of a mechanical pencil

  2. kinetic energy over potential energy

  3. the energy of mechanisms in a robot

  4. potential energy + kinetic energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mechanical energy is defined as the sum of an object's kinetic energy and its potential energy. It represents the total energy associated with the motion and position of an object.

Multiple choice

As the cars of a rollercoaster race down a hill, energy transformations take place. Which of the following is true?

  1. some energy is destroyed as the car slows down

  2. potential energy is transformed to kinetic energy and other forms of energy

  3. the kinetic energy of the cars is equal to the potential energy of the cars

  4. kinetic energy is stored while the car moves down the hill
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As a rollercoaster descends, gravitational potential energy is converted into kinetic energy. Some energy is also lost to the surroundings as heat and sound due to friction and air resistance.

Multiple choice

Potential energy is sometimes called ____ energy.

  1. stored

  2. moving
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Potential energy is the energy held by an object because of its position relative to other objects, stresses within itself, or its electric charge. It is often referred to as stored energy.