Physics
Grade-9
Easy

Question

A particular chemical process has an energy efficiency of only 3.00%. To complete this large-scale chemical process, 140,000 J of energy is input. What is the useful energy output of this process?

  1. 4000 J
  2. 4200 J
  3. 40000 J
  4. 420000 J

hintHint:

Efficiency (%) = (useful energy output ÷ energy input) × 100

The correct answer is: 4200 J


    Efficiency (%) = (useful energy output ÷ energy input) × 100
    O u t p u t equals fraction numerator E f f i c i e n c y cross times I n p u t over denominator 100 end fraction equals fraction numerator 3 cross times 140000 over denominator 100 end fraction equals 4200 J

    Related Questions to study

    Grade-9
    Physics

    A construction worker puts 20 J of energy in to one strike of his hammer on the head of a nail. The energy transferred to the act driving the nail in to the wood is 8.0 J. What is his efficiency of hammering?

    A construction worker puts 20 J of energy in to one strike of his hammer on the head of a nail. The energy transferred to the act driving the nail in to the wood is 8.0 J. What is his efficiency of hammering?

    PhysicsGrade-9
    Grade-9
    Physics

    A technician examines different electrical devices to determine the one that is the most energy efficient. While conducting a test, he notes that one of these devices consumes 650 000 J of energy and loses 315 000 J at the same time. What is the energy efficiency of this device?

    A technician examines different electrical devices to determine the one that is the most energy efficient. While conducting a test, he notes that one of these devices consumes 650 000 J of energy and loses 315 000 J at the same time. What is the energy efficiency of this device?

    PhysicsGrade-9
    Grade-9
    Physics

    The table below has three different hairdryer models. Which is the least energy-efficient model?

    The table below has three different hairdryer models. Which is the least energy-efficient model?

    PhysicsGrade-9
    parallel
    Grade-9
    Physics

    An oven consumes 525 kWh of energy to provide 386 kWh of useful energy. What is its percentage efficiency?

    An oven consumes 525 kWh of energy to provide 386 kWh of useful energy. What is its percentage efficiency?

    PhysicsGrade-9
    Grade-9
    Physics

    A television that is 83% efficient provides 5200 J of useful energy. How much energy does it consume?

    A television that is 83% efficient provides 5200 J of useful energy. How much energy does it consume?

    PhysicsGrade-9
    Grade-9
    Physics

    A computer that is 87% efficient consumes 475 kWh of energy. How much useful energy does it provide?

    A computer that is 87% efficient consumes 475 kWh of energy. How much useful energy does it provide?

    PhysicsGrade-9
    parallel
    Grade-9
    Physics

    Which of these is not a wise choice as an energy-conscious person?

    Which of these is not a wise choice as an energy-conscious person?

    PhysicsGrade-9
    Grade-9
    Physics

    Which of the following operates at low temperatures?

    Which of the following operates at low temperatures?

    PhysicsGrade-9
    Grade-9
    Physics

    A device gives out 500 J of heat energy as useful work. Determine the energy supplied to it as input if its efficiency is 40%.

    A device gives out 500 J of heat energy as useful work. Determine the energy supplied to it as input if its efficiency is 40%.

    PhysicsGrade-9
    parallel
    Grade-9
    Physics

    To increase the efficiency of energy use, we could

    To increase the efficiency of energy use, we could

    PhysicsGrade-9
    Grade-9
    Physics

    Which reading is greater?

    Which reading is greater?

    PhysicsGrade-9
    Grade-9
    Physics

    A cyclist puts 600 J of work on his bicycle and the bicycle gives out 140 J of useful work. Calculate the energy efficiency of the cyclist.

    A cyclist puts 600 J of work on his bicycle and the bicycle gives out 140 J of useful work. Calculate the energy efficiency of the cyclist.

    PhysicsGrade-9
    parallel
    Grade-9
    Physics

    A certain appliance requires 1,755 watts. How much would it cost to run the appliance for a total of 33 minutes at a cost of Rs10 per kWh?

    A certain appliance requires 1,755 watts. How much would it cost to run the appliance for a total of 33 minutes at a cost of Rs10 per kWh?

    PhysicsGrade-9
    Grade-9
    Physics

    A certain appliance requires 2,141 watts. How much would it cost to run the appliance for a total of 27 minutes at a cost of Rs 12 per kWh?

    A certain appliance requires 2,141 watts. How much would it cost to run the appliance for a total of 27 minutes at a cost of Rs 12 per kWh?

    PhysicsGrade-9
    Grade-9
    Physics

    The law of conservation of energy states that when one form of energy is converted into another

    The law of conservation of energy states that when one form of energy is converted into another

    PhysicsGrade-9
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.