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 botany sustainable development with equity sustainable management conservation sustainable development

Electricity is one of the primary needs of human society.

  1. True

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

Electricity is one of the primary needs of human society. Electricity is crucial in human life to remove poverty, economic growth, and improved lifestyles. Even low voltage electricity make much difference in the remote areas. Village areas where there is no electricity are facing many difficulties after natural light i.e. when there is no sunlight. They are unable to do their works at home and cannot move in the streets if there are any emergencies like major health issues

So, the correct answer is 'True'

Multiple choice physics work and energy commercial unit of energy power work and power

Electric energy supplied to homes is measured by

  1. voltmeter

  2. ammeter

  3. galvanometer

  4. kilowatt-hour meter
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The kilowatt hour (symbolized kW⋅h as per SI) is a composite unit of energy equivalent to one kilowatt (1 kW) of power sustained for one hour. One watt is equal to 1 J/s. One kilowatt hour is 3.6 MJoules, which is the amount of energy converted if work is done at an average rate of one thousand watts for one hour.

Multiple choice physics work and energy commercial unit of energy power work and power

Biggest commercial unit of energy.

  1. $kwh$
  2. $BOT$
  3. $kVAh$

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

The biggest commercial unit of energy is kilowatt hour $\left(kwh\right)$. It is also known as kilo-volt-ampere hour $\left(kVAh\right)$ and board of trade unit (BOT) or simply electric unit.

Multiple choice physics work and energy commercial unit of energy power work and power

When we pay for our electricity bill, we are paying for the ____________.

  1. charge used

  2. current used

  3. power used

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

A unit is defined as $kWh$, means a $1000 joule/ sec$ is used for $1 hour$ ,

$1KwH=1000\times 3600=3.6\times10^6joules$
we pay for unit and that is energy 

Multiple choice physics friction advantages and disadvantages of friction merits and demerits of friction and methods to reduce it friction: a necessary evil

Friction reduces efficiency of machines due to:

  1. Production of heat

  2. Wearing out of moving parts

  3. Increase in energy consumption

  4. AlI of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Answer is D.

Efficiency is relate to energy conversion performance. A system that can convert energy entirely and completely into energy of another form performs the conversion at 100% efficiency. 
The heat produced by friction cannot be used to recover 100% of the mechanical energy that was converted into heat, the effect of friction is to reduce the (energy conversion) efficiency of machines. 
The parts of the machine wear and tear due to contimuous usage.
More the friction more the enrgy consumption.
Hence, all the options are correct.

Multiple choice chemistry electrolysis electrolytes and non-electrolytes introduction to electrolysis chemical reactions

An electrochemical cell converts __________ energy to ____________ energy.

  1. Chemical

  2. Increases

  3. Electrical

  4. Ions
Reveal answer Fill a bubble to check yourself
A,C Correct answer
Explanation

An electrochemical cell converts chemical energy to electrical energy. An electrochemical cell has two electronic conductors such as metal plates or carbon rods dipped into an electrolytic or ionic conductor which is an aqueous electrolytic solution or a pure liquid of an electrolyte.

Multiple choice types of cells electricity physics

Three types of electric cells which provide current are:

  1. Button cell, solar cell & secondary ceil

  2. Solar cell, electrolytic cell, electro chemical cell

  3. (A) and (B) both are correct

  4. Neither (A) nor (B) is correct
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Answer is C.

When a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity and is useless. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. 
The types of cells mentioned in option A and option are correct.
Hence, option C is correct.

Multiple choice types of cells electricity physics

In daily life, dry cell is used in 

  1. Fan

  2. Alarm clock

  3. Tubelight

  4. All out(Mosquito repellant)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Alarm clock uses Dry Cell. Rest of the components work on power supply.

Multiple choice types of cells electricity physics

Nickel Cadmium cells are used in

  1. very long-life applications

  2. devices with high limitation on spaces.

  3. portable machines that run on electricity.

  4. all of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Nickel cadmium cells are used in portable machines that run on electricity. It is rechargeable.