Physics practice test

ENERGY QUIZ (Grade 9–10)

Section A: Multiple Choice (1 mark each)

  1. What is energy?
    A. The speed of an object
    B. The ability to do work-Answer
    C. A type of force
    D. A form of matter

  2. Which of the following is kinetic energy?
    A. A stretched rubber band
    B. A moving car-Answer
    C. A book on a shelf
    D. A charged battery

  3. Which type of energy is stored in food?
    A. Heat energy
    B. Chemical energy-Answer
    C. Light energy
    D. Electrical energy

  4. Which energy store increases when an object is lifted?
    A. Kinetic
    B. Chemical
    C. Gravitational potential-Answer
    D. Sound

  5. Which of the following is an example of energy transformation?
    A. A stationary ball
    B. A battery losing charge
    C. A torch converting chemical energy to light-Answer
    D. A book staying on a table

  6. The Law of Conservation of Energy states:
    A. Energy can be destroyed
    B. Energy is always increasing
    C. Energy cannot be created or destroyed, only transferred-Answer
    D. Energy only exists in moving objects

  7. Which energy type is associated with vibrations?
    A. Sound energy-Answer
    B. Nuclear energy
    C. Chemical energy
    D. Electrical energy

  8. Which appliance is MOST energy efficient?
    A. 100W bulb producing lots of heat
    B. LED bulb producing mostly light-Answer
    C. Heater with energy loss
    D. Old incandescent lamp

Section B: Short Answer (2–3 marks each)

  1. Define:
    a) Kinetic energy- Kinetic energy is energy that has movement, whether its vibrations, waves, or just point A-B
    b) Potential energy- Potential energy is energy that is stored in an object due to its position or state, such as chemical energy, gravitational energy, or elastic energy.

  2. List 4 types of energy and give an example of each.

: Sound energy- Radio

: Thermal energy-A hot stove

:Radiant energy- the suns light

: Gravitational potential energy: An object lifted above ground but not dropped yet

  1. What is energy transformation? Give one real-life example: Energy transformation is when energy transfers from one type of energy to another due to a change in position or state. An example would be when potential gravitational energy changes into kinetic energy when an object is dropped from above.

  2. A rubber band is stretched and released.
    Describe the energy changes. Elastic potential energy——→ kintetic energy from the movemnet of band, wasted energy such as sound and thermal (eg: snap of band, friction of band and finger)

  3. What is energy efficiency?

Energy efficiency is the ability of an object to produce the same amount of useful energy with less input work, thereby minimizing energy waste during the process.

  1. Why is some energy always “wasted” in energy transfers?: Because some energy, dissipated energy, is transformed into forms that are not useful for performing work, such as heat or sound, which results in a decrease in overall efficiency.

Section C: Energy Transformations (3–4 marks each)

  1. A torch is switched on.
    Describe the energy transformations involved.

Chemical energy from body——>mechanical energy from finger pushing down on button——> chemical energy in cell battery—→electrical energy——>light energy+thermal energy

  1. A car engine is running.
    Identify:

  • Useful energy output—→Kinetic energy

  • Wasted energy—→thermal energy/sound energy

  1. A solar panel powers a light bulb.
    Describe the full energy transformation chain.

Radiant energy from sun——> electrical energy in the solar panel, which is then converted into useful energy output—> kinetic energy to power the light bulb, while some energy is wasted as thermal energy and sound energy during the process.

  1. A fan is turned on.
    What energy changes occur? Mechanical energy——> electrical energy—→ kinetic energy and sound energy

Section D: Application & Thinking (4–5 marks each)

  1. Explain how using energy-efficient appliances reduces:

  • Energy use

  • Cost

Using energy-efficient appliances reduces energy use due to it producing the same amount of energy required while requiring less effort, and reduces cost by minimizing electricity bills over time. Furthermore, these appliances contribute to reducing greenhouse gas emissions, as they consume less power from fossil fuel sources.

  1. Compare an LED bulb and an incandescent bulb in terms of efficiency.

  2. A student says:
    “Energy is lost when a ball stops bouncing.”
    Explain why this is incorrect using the Law of Conservation of Energy.

This statement is incorrect as according to the law of conservation of energy, energy cannot be created or destroyed, only transferred from one thing to another. When a ball stops bouncing, its meereily transferring energy to the surrounding environment in terms of sound and heat, rather than losing it completely. The energy that was initially in the ball is converted to these forms, demonstrating that energy is conserved throughout the process.

  1. A Bunsen burner heats water.
    Explain:

  • Useful energy-Thermal

  • Wasted energy-Sound/light

  • Why efficiency is less than 100%- because some energy is watsed/not useful

Section E: Data & Diagrams

  1. Draw (or describe) a simple energy flow diagram for a toaster.

Input energy(electrical energy from outlet)———>thermal energy (heat) for toasting bread. The thermal energy is then partially transformed into the internal energy of the bread, causing it to heat up and become toasted———→

  1. What is a Sankey diagram? What does the width of the arrows represent?

A Sankey diagram is a diagram used to showcase the total input energy, useful energy, dissapated energy, and overall all types of energies that are used and in what amount. The width of the arrow represents the proportion of energy possesed.

  1. A device uses 100 J of energy and produces 60 J of useful energy.
    Calculate efficiency.

  2. 60/100 ×100= 60%

Section F: Scientific Skills (6 marks)

  1. A student investigates how stretch length affects how far an eraser travels.

Write a scientific conclusion:

  • State if results support hypothesis

  • Explain scientifically

  • Evaluate method (fairness, reliability, precision)

  • Suggest 2 improvements