RADT 1065 Photon and EMR Quiz

A 1 tesla MRI device operates at a radiofrequency of 42 MHz. What is the wavelength of this radiation?

7.1 m

A photon of red light has a ______ wavelength than a photon of green light.

longer

A radiograph produced at an SID of 100 cm results in an exposure of 1 mGya (100 mR). What would be the exposure if the SID were reduced to 90 cm?

1.23 mGya

A single unit of electromagnetic radiation is also called a/an:

photon

For any EM radiation, an increase in frequency results in

an increase in energy

If the exposure rate 1 m from a source is 90 mGya/h, what is the exposure rate 3 m from the source?

10mGya/hr

In radiographs of bony structures embedded in soft tissue, the bone is:

radiopaque

The EM spectrum includes

X-rays and radar with the speed of light in a vacuum

The expression that relates x-ray energy and wave- length through Planck's constant is

E = hc/l

The frequency of electromagnetic radiation is

measured in hertz

The inverse square law states that

Intensity is inversely proportional to the square of the distance

The principal difference between x-rays and gamma rays is their

origin

When the EM spectrum is considered, photons of a radio broadcast have relatively _______ energy and ______ wavelengths.

Low energy and long wavelengths

When the frequency of electromagnetic radiation is increased tenfold, the wavelength...

decreases to 1⁄10

When white light is refracted through a prism, the following colors are emitted. Which has the longest wavelength?

red

Which of the following has a constant value for all electromagnetic radiation?

velocity

Which of the following is true for both a 100 keV x-ray and a 10 keV gamma ray

they have zero mass

Which of the following types of radiation would be classified as EM?

-5 MHz therapeutic ultrasound

-30 m radio broadcast

-1000 Hz sound

-Beta radiation

30 m radio broadcast

Which type of electromagnetic radiation is not used for medical imaging?

microwaves

X-ray wavelength is

inversely proportional to frequency