Energy and Wave Phenomena Flashcard

Front

What type of energy transfer occurs when the sun heats the Earth's surface?

Back

Radiation

Answer explanation

The sun heats the Earth's surface through radiation, which is the transfer of energy in the form of electromagnetic waves. Unlike conduction and convection, radiation does not require a medium to transfer heat.

Front

Which of the following best describes energy conservation?

Back

Energy cannot be created or destroyed, only transferred or transformed.

Answer explanation

The correct choice states that energy cannot be created or destroyed, only transferred or transformed. This principle, known as the law of conservation of energy, emphasizes that energy changes forms but is always conserved.

Front

What type of energy transfer occurs when you touch a metal spoon left in a hot pot?

Back

Conduction

Answer explanation

When you touch the metal spoon, heat is transferred directly from the hot spoon to your hand through direct contact. This process is known as conduction, where thermal energy moves through materials.

Front

Wireless signals used in cell phones are transmitted using: Sound waves, Microwaves, X-rays, Infrared waves

Back

Microwaves

Answer explanation

Wireless signals in cell phones are transmitted using microwaves, which are a type of electromagnetic radiation. They allow for efficient communication over long distances, unlike sound waves, X-rays, or infrared waves.

Front

A microwave oven heats food by emitting: Infrared waves, Ultraviolet radiation, Microwaves, Gamma rays

Back

Microwaves

Answer explanation

A microwave oven heats food by emitting microwaves, which are a type of electromagnetic radiation. These waves excite water molecules in the food, generating heat and cooking it. Other options like infrared and gamma rays are not used.

Front

Example of wave reflection:

Back

An echo in a canyon

Answer explanation

An echo in a canyon is a clear example of wave reflection, as sound waves bounce off the canyon walls and return to the listener. The other options involve different phenomena, such as refraction or signal attenuation.

Front

When light enters a glass prism and bends, this is an example of:

Back

Refraction

Answer explanation

When light enters a glass prism, it changes speed and direction, which is known as refraction. This bending of light occurs due to the change in medium from air to glass.

Front

Which type of wave interference occurs when two waves combine to make a larger wave?

Back

Constructive interference

Answer explanation

Constructive interference occurs when two waves combine in phase, resulting in a larger wave. This is the opposite of destructive interference, where waves combine out of phase and reduce amplitude.

Front

What property of waves makes fiber optic cables useful for transmitting information over long distances?

Back

Total internal reflection

Answer explanation

Fiber optic cables utilize total internal reflection, allowing light to be transmitted over long distances with minimal loss. This property ensures that light signals remain contained within the fiber, making them efficient for communication.

Front

The phenomenon that makes sunglasses reduce glare is:

Back

Polarization

Answer explanation

Sunglasses reduce glare primarily through polarization, which filters out horizontal light waves that cause glare, allowing only vertical waves to pass through. This enhances visual comfort and clarity.