Useful And Wasted Energy From Electrical Devices Quiz

1. What types of energy does a Light Bulb convert into?

Useful - LightWasted- Heat

Useful - Heat, Wasted - Light

Useful - Sound, Wasted - Motion

Useful - Electric, Wasted - Radio waves

A light bulb primarily converts electrical energy into light energy, which is useful, and heat energy, which is wasted. The incorrect answers provide combinations of energy types that do not align with how light bulbs operate.

Explanation

A light bulb primarily converts electrical energy into light energy, which is useful, and heat energy, which is wasted. The incorrect answers provide combinations of energy types that do not align with how light bulbs operate.

2. What is the function of an electrical heater?

Wasted - Emits sound when in operation

Wasted - Emits light from the glowing element

Wasted - Generates excessive magnetic fields

Useful - Thermal energy to the surroundingswasted - light from the glowing element.

Electrical heaters convert electrical energy into heat energy, which is then transferred to the surroundings to warm up the environment. The light emitted from the glowing element is considered a byproduct and not the main function of the heater.

Explanation

Electrical heaters convert electrical energy into heat energy, which is then transferred to the surroundings to warm up the environment. The light emitted from the glowing element is considered a byproduct and not the main function of the heater.

3. What is the consequence of using an electrical toaster?

Useful - heating up the surrounding air; Wasted - heating the toaster coils

Useful - thermal energy of breadwasted - thermal energy of toaster case and air around it.

Useful - generating light; Wasted - draining electrical power

Useful - cooling the toaster case; Wasted - toasting the bread unevenly

When using an electrical toaster, the intended outcome is for the thermal energy to be transferred to the bread for toasting, which is the useful aspect. However, a significant amount of thermal energy is also lost to the toaster case and the air around it, representing wasted energy.

Explanation

When using an electrical toaster, the intended outcome is for the thermal energy to be transferred to the bread for toasting, which is the useful aspect. However, a significant amount of thermal energy is also lost to the toaster case and the air around it, representing wasted energy.

4. How does a hairdryer work?

Incorrect - Magic

Useful - heat energy of air flowing past the heater filament and kinetic energy of air driven by fan

Incorrect - Telekinesis

Incorrect - Time travel

A hairdryer works by utilizing the heat energy generated by air flowing past the heater filament and the kinetic energy of air driven by the fan. It does not operate through magic, telekinesis, or time travel.

Explanation

A hairdryer works by utilizing the heat energy generated by air flowing past the heater filament and the kinetic energy of air driven by the fan. It does not operate through magic, telekinesis, or time travel.

5. What are the key components of energy transfer associated with an electric motor?

Useful- sound energy of motor. Wasted- potential energy of objects lifted with motor.

Useful- thermal energy of objects lifted with motor.then sound energy of motor. Wasted- kinetic energy of object driven by motor.

Useful- potential energy of object driven by motor. Wasted- thermal energy of motor.

Useful- kinetic energy of object driven by motor.and potential energy of objects lifted with motorwasted - thermal and sound energy of motor

The correct answer describes the useful kinetic and potential energy transfer and the wasted thermal and sound energy in an electric motor.

Explanation

The correct answer describes the useful kinetic and potential energy transfer and the wasted thermal and sound energy in an electric motor.

6. What is the main difference between the useful and wasted energy in a personal stereo?

Useful - potential energy of object; Wasted - sound energy

Useful - electrical energy; Wasted - light energy

Useful - thermal energy of motor; Wasted - kinetic energy of object

Useful -kinetic energy of objectsoundwasted - thermal energy of motor.

In a personal stereo, the useful energy is in the form of kinetic energy of the object (such as the moving parts of the stereo) that contributes to its function. The wasted energy is mainly in the form of thermal energy generated by the motor, which is not useful for the intended purpose of playing sound.

Explanation

In a personal stereo, the useful energy is in the form of kinetic energy of the object (such as the moving parts of the stereo) that contributes to its function. The wasted energy is mainly in the form of thermal energy generated by the motor, which is not useful for the intended purpose of playing sound.

7. What energy is stored in a computer disc drive?

Wasted - energy stored in batteries powering the disc drive

Wasted - sound energy of the motor that drives the disc

Wasted - thermal energy of the motor that drives the disc

Useful - energy stored in magnetic dots on discwasted - thermal and sound energy of the motor that drives the disc.

The correct answer explains that the energy stored in magnetic dots on the disc is useful, while the thermal and sound energy of the motor that drives the disc is wasted. The incorrect answers provide alternative options that do not accurately describe the energy stored in a computer disc drive.

Explanation

The correct answer explains that the energy stored in magnetic dots on the disc is useful, while the thermal and sound energy of the motor that drives the disc is wasted. The incorrect answers provide alternative options that do not accurately describe the energy stored in a computer disc drive.