Energy test

21 important questions on Energy test

What percentage of air consists of oxygen?

  • Oxygen: 20%

What three things are required for combustion?

  1. Flame/fuel
  2. Oxygen
  3. Heat

Give an example of input and output energy using a battery-powered toy.

  • Input: Batteries in the toy.
  • Output: Toy moves or makes sounds.
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

What is required to start burning fuels?

  • Fuels need energy to start burning.
  • Example: A burning match provides input energy.

Explain input and output energy using food.

  • Input: Food consumed.
  • Output: Energy for running, playing, doing things.

What is coal and how is it formed?

  • Coal: a fossil fuel from ancient plants.
  • Formed under Earth's pressure.
  • Plants buried and transformed over time.

How does burning fuel release energy?

  • Unlocks stored energy
  • Molecules react with oxygen
  • Releases heat and light

What happens when fuels start burning?

  • Stored energy is released.
  • Energy changes to heat and light.

What is the useful output energy of coal?

  • Used for: Cooking, electricity.
  • Output: Heat energy.

What type of energy do petrol and diesel provide to cars?

  • Cars receive energy from
    • Petrol
    • Diesel
  • This enables them to move.

How do different fuels release energy?

  • Different amounts of energy stored
  • Gasoline releases quickly
  • Wood or coal release slowly, steadily

How does food provide energy to humans?

  • Humans gain energy from food
  • Helps them
    • Function
    • Grow
    • Move

What happens when we use fuels?

  • Tap into stored energy
  • Power cars, heat homes
  • Unlock fuel molecules

What are the uses and output energy of wood?

  • Used for: Heating, cooking.
  • Output: Heat energy.

What energy transformation occurs in candles?

  • Candles produce
    • Heat energy
    • Light energy
  • Convert stored chemical energy.

How does paraffin work when heated?

  • Heat melts paraffin to gas.
  • Gas burns to create a flame.
  • Used in lamps and stoves.

Describe uses and output energy of petrol.

  • Used for: Fueling vehicles.
  • Output: Mechanical energy.

How does fire contribute to cooking?

  • Fire produces heat energy
  • Used to cook food on a braai.

What happens when wax melts?

  • Melts into liquid when warm.
  • Liquid travels up wick.
  • Turns to gas, creating flame.

How do fuels store energy?

  • Ingredients storing energy
  • Used by cars, jets, and machines

What is gas and its property?

  • No shape or size.
  • Burns to release energy.
  • Provides heat and light.

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo