AS - Doppler effects, EM spectrum and Polarisation

The energy that an electromagnetic wave carries is directly proportional to ...

• its wavelength

• its speed

• its amplitude

• its frequency

• its displacement

Which of the following electromagnetic waves has the lowest energy?

• gamma ray
• infrared wave
• visible light wave
• microwave

As the wavelength of an electromagnetic wave increases, the amount of energy in that wave carries ...

• increases.
• decreases.
• stays the same.

The pitch of a sound wave relates to the wave's _________________.

• Amplitude

• Frequency

• Wavelength

• Period

What is the Doppler Effect?

• A change in frequency due to the relative motion of a wave source and an observer

• Thing happens When a wave overlaps with another wave

• Thing happens When a wave bounces off of another object

• Thing happens When a wave bends due to traveling through a different medium

• Thing happens when a wave pass through a narrow gap.

You are driving in a car and honk the horn at a person standing in the street. As you approach the person, what happens to the pitch of the horn according to you in the car?

• It increases

• It decreases

• It stays the same because you are in the car moving with the sound.

Look at the picture. Who is experiencing a higher pitched sound?

• Observer A

• Observer B

• There's no difference

A car moves at 20 m/s away from a whistle. The whistle is stationary. The whistle makes a sound with a frequency of 500 Hz. The speed of sound in air is 330 m/s.

What is the frequency observed by the driver of the car?

• 530 Hz

• 470 Hz

• 520 Hz

You stand on the sidewalk next to the street. A fire truck is away from you. The frequency of the siren on the fire truck is 600 Hz.

What should you hear?

• Frequency higher than 600 Hz

• Frequency lower than 600 Hz

• Exactly 600 Hz

• No sound, silence.

A car moves at 20 m/s towards a whistle. The whistle is stationary. The whistle makes a sound with a frequency of 500 Hz. The speed of sound in air is 330 m/s.

What is the frequency observed by the driver of the car?

• 530 Hz

• 470 Hz

• 480 Hz