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 evs - i substances, objects and energy renewable and non-renewable resources renewable and non-renewable sources of energy solar energy and its applications renewable resources alternative fuels and energy sources alternative sources of energy

A good source of energy would be the one which would do a _______ amount of work per unit volume of mass. Any source of energy we use to do work is consumed & _______ used again.

  1. larger, can be

  2. smaller, can be

  3. larger, cannot be

  4. smaller, cannot be
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A good source of energy would be the one which would do a larger amount of work per unit volume of mass. Any source of energy we use to do work is consumed & cannot be used again.
A good source of energy should have the following characteristics:
  1. It should do a large amount of work per unit mass or volume - it means that the output energy must be more than the input energy. It should have high calorific value.
  2. It should be easily accessible - the energy source should be able to provide energy over a long period of time. Example: coal and petroleum.
  3. Should be easy to store and transport - most common sources of energy such as coal, petrol and LPG need to be transported to users from their points of production. They also need proper storage. Thus it is important to store and transport these sources safely and economically.
  4. Safe and convenient to use - energy sources should be safe as it is used by a large number of people and should be convenient.
Multiple choice physics static electricity explaining static electricity charging by induction electric charges and fields

An application of electrostatic induction is

  1. electric generator

  2. Van de Graff generator

  3. Wimhurst machine

  4. transformer
Reveal answer Fill a bubble to check yourself
B,C Correct answer
Explanation

Electrostatic induction is a redistribution of electrical charges in an object caused by the influence of nearby charges. Electrostatic generators such as the Wimshurst machine, the Vande Graph generator use this principle. 

Multiple choice physics solar equipment production of electricity from solar energy solar power alternate sources of energy solar power plant solar energy and its applications renewable and non-renewable resources renewable and non-renewable sources of energy generation of electricity

Of the following converts light energy into electrical energy?

  1. Motor

  2. Battery

  3. Solar cell

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

A solar cell is specifically designed to convert light energy into electrical energy.

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

Which of the following batteries are responsible for direct environmental hazard?

  1. Alkaline dry cell

  2. Mercury cell
  3. $Ni-Cd$ battery

  4. Lithium battery
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Alkaline batteries are prone to leaking potassium hydroxide, a caustic agent that can cause respiratory, eye and skin irritation. Potassium, if it leaks, can cause severe chemical burns thereby affecting the eyes and skin.

Mercury can even be absorbed through the skin. These harmful substances permeate into the soil, groundwater and surface water through landfills and also release toxins into the air when they are burnt in municipal waste combustors.

For humans, both lead and cadmium can be taken only by ingestion or inhalation.  Moreover, cadmium is easily taken up by plant roots and accumulates in fruits, vegetables and grass. The impure water and plants in turn are consumed by animals and human beings, who then fall prey to a host of ill-effects.

Since Li-ion batteries contain less of toxic metals than other types of batteries which may contain lead or cadmium, they are generally categorized as non-hazardous waste. 

A, B and C are correct options.

Multiple choice chemistry occurrence of carbon compounds in nature substances, objects and energy alternative fuels and energy sources alternative sources of energy

We can save energy by :

  1. buying expensive cars

  2. using aeroplanes

  3. using CFL

  4. using ships
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Simple things like switching off fans and lights when not in use, using maximum daylight, walking instead of driving for short distances, using CFL instead of traditional bulbs, proper insulation for leakage of energy can go a long way in saving energy.


Hence the correct option is C.

Multiple choice metallic and electrolytic conduction electrolysis chemical reactions electrochemistry chemistry

An electrolytic cell was set up. Distilled water is placed in the cell and battery is switched on. The bulb is also connected through a battery. The bulb will:

  1. glow

  2. not glow

  3. partially glow

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

Distilled water is a bad conductor of electricity. It do not contains any impurities to carry the current. So the circuit will not be completed for the bulb to glow.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

A battery lights a bulb. The electric energy on flowing through the filament of the bulb, first changes into ______ energy and then into the _______ energy.

  1. heat; light

  2. light; heat

  3. mechanical; heat

  4. mechanical; light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Within the electric cell or battery, the chemical energy changes into electrical energy. The electric energy on flowing through the filament of the bulb, first changes into heat energy and then into the light energy.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

In steam engine:

  1. Mechanical energy is converted to heat energy

  2. Heat energy is converted to mechanical energy

  3. Heat energy is converted to electrical energy

  4. Heat energy is converted to chemical energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heat is used to generate steam which moves the pistons and thereby converting heat energy to mechanical energy.