Jr2: Energy and Electricity

Which of the following energy transformations occur when a lamp that is plugged into a wall socket is functioning correctly?

• Chemical to light

• Electrical to chemical

• Electrical to light

• Chemical to electrical

Which of the following devices transforms electrical energy into mechanical energy?

• An e-reader

• a fan

• a manual pencil sharpener

• ipad

Which of these is an example of light energy being transformed into chemical energy?

• A glow stick lights up when broken.

• Water heated by the sun evaporates.

• A plant makes sugar in the sunlight.

• A battery causes a buzzer to vibrate.

The Theory of the Conservation of Energy states -

• Energy can be created, just not destroyed. It changes its form from one type to another.

• Energy can never be created nor destroyed. It can only change its form from one type to another.

• The total energy in our Universe changes, as different forms of energies can be transformed from each other under certain circumstances.

• Energy transformations do not passively occur in our lives, rather we actively make use of energies and transform energies.

The unit used to measure work is the __________.

• watt

• newton

• joule

• meter

A 5000N block is lifted 10 m. How much work was done?

• 50000 J

• 5000 J

• 500 J

• 50 J

In which of these cases is work being done? 

• A student sleeps

• A student pushes a locked door that does not move

• A student carries his chair into another room

• A student sits on the carpet

True or false: when the distance an object moves is zero the work done on the object is also zero.

• True

• False

If you move an object a greater distance, _________.

• you have more power

• you do more work

• you do the work faster

• you do less work

If you lift an 5 N object 2 m and then lift a 10 N object 2 m. which is TRUE?

• you do the same amount of work

• you are more powerful when you move the 5 N object

• you do more work when you move the 10 N object

• you use the same amount of force