Ch5 - L1 Blackbody radiation and photoelectric effect

The given graph represents the intensity of the light emitted by three black bodies. Which of the following is true about their temperatures?

• A

• B

• C

• they have same temprture.

The following graph represents the relation between the radiation intensity and the wavelength of the radiation emitted by two objects A and B. Which of the following is true (if any) about the temperatures of A and B?

• The temperature of A is the same as the temperature of B

• The temperature of A is greater than the temperature of B

• The temperature of A is less than the temperature of B

• None of the answers are correct.

What is the difference in energy between a photon with a wavelength of 400 nm and a photon with a wavelength of 700 nm?

A certain radio station emits radio waves at a frequency of 100.6 MHz. The energy of a photon at this frequency is equal to ……..

The ratio between the frequencies of two photons is 1∶3. The ratio between their energies is …………….

• 1:9

• 3:1

• 1:3

• 9:1

Photon A has a wavelength that is four times that of photon B. What is the ratio of the energy of photon A to the energy of photon B?

• 2

• 1/4

• 1/2

• 4

What is the frequency of a photon that has an energy of 3.00 eV?

In an experiment that tests the photoelectric effect, a monochromatic light ray falls on a surface and frees several electrons from that surface. If this monochromatic light ray is replaced with another with higher energy and the same intensity, the number of the ejected electrons ……….

• will increase

• will not change

• will decrease

• Not enough information is provided.

In a cathod raytube if the potential diffrence between cathod and anode increased four times, the max speed of the electrons ........

• decreases to half

• doesn't change

• gets doubles

• gets quadrupled