When a teacher shines light on a photocell
attached to a fan, the blades of the fan turn. The
brighter the light shone on the photocell, the
faster the blades turn. Which energy conversion
is illustrated by this demonstration?
(1) light → thermal → mechanical
(2) light → nuclear → thermal
(3) light → electrical → mechanical
(4) light → mechanical → chemical

3 - Light Electrical Mechanical

The light energy emitted by the light is converted by the photocell to electrical energy, and then supplied to the fan blades which turn ie Kinetic/Mechanical energy.

Answer Link

shirleywashington shirleywashington · Answer 2 · 2019-02-25T12:27:48+01:00

Answer: The energy conversion is " light → electrical → mechanical ".

Explanation :

Light is the form of energy that enables us to see distant objects clearly.

Electrical energy is the energy which is possessed by the movement of electric charges.

Mechanical energy is the sum of potential and kinetic energy.

In the given scenario, when a teacher shines a light on a photocell attached to a fan, the blades of the fan turn. In this part, the light energy is transformed into electrical energy.

The brighter the light shone on the photocell, the faster the blades turn. Here, the electrical energy gets converted to mechanical energy.

So, the correct option is (c) " light → electrical → mechanical ".