Q: Which equation describes the intensity $$I at a $$point on a screen in a double-slit experiment?

$$I = I_0$ \cos^2$ \left( \frac{\pi d \sin \theta}{\lambda} \right)$$

Question 1

Which of the following best describes the principle behind the photoelectric effect?

Accepted Answer

Electrons are emitted from a metal surface when it absorbs photons with energy greater than the work function.

Question 2

A beam of monochromatic light passes through a single slit of width $$a$$ and produces a diffraction pattern on a screen. Which equation gives the angular position $$	heta of $$the first minimum?

Accepted Answer

$$a \sin 	heta = \lambda$$

Question 3

Which statement about the uncertainty principle is correct?

Accepted Answer

It states that the product of the uncertainties in position and momentum is at least $$\frac{\hbar}{2}.$$

Question 4

A hydrogen atom emits a photon as an electron transitions from $$n=3 to$$ $$n=2. $$Which formula gives the energy of the emitted photon?

Accepted Answer

$$E = 13.6 \left( \frac{1}{n_1$^2} - \frac{1}{n_2$^2} \right) eV$$

Question 5

Which of the following is a consequence of the wave-particle duality of light?

Accepted Answer

Light exhibits both interference and photoelectric effect phenomena.

Question 6

A photon has energy $$E = 3.0 	imes 10$$^{-19}$$ J. What is its wavelength?

Accepted Answer

$$\lambda = \frac{hc}{E}$$

Question 7

Which equation describes the intensity $$I at a $$point on a screen in a double-slit experiment?

Accepted Answer

$$I = I_0$ \cos^2$ \left( \frac{\pi d \sin 	heta}{\lambda} ight)$$

Question 8

Which of the following best explains why X-rays can be used to determine the structure of crystals?

Accepted Answer

X-rays have wavelengths comparable to the spacing between atoms in a crystal.

Question 9

Which formula gives the de Broglie wavelength of a particle with momentum $$p$$?

Accepted Answer

$$\lambda = \frac{h}{p}$$

Question 10

A radioactive isotope decays with a half-life of 5 years. What fraction of the original sample remains after 15 years?

Accepted Answer

$$\frac{1}{8}$$

Question 11

Which of the following is NOT a property of electromagnetic waves?

Accepted Answer

They require a medium to propagate.

Question 12

Which equation represents the energy-mass equivalence principle?

Accepted Answer

$$E = mc^2$

Question 13

A laser emits light of wavelength $$500 nm. $$What is the frequency of the light?

Accepted Answer

$$f = \frac{c}{\lambda}$$

Question 14

Which of the following phenomena demonstrates the quantization of energy levels in atoms?

Accepted Answer

Discrete line emission spectrum

Question 15

Which equation gives the relationship between energy $$E$$ and frequency $$f$$ for a photon?

Accepted Answer

$$E = hf$$

Question 16

Which of the following is a correct statement about the Compton effect?

Accepted Answer

It shows that photons can transfer energy and momentum to electrons.

Question 17

A particle is confined in a one-dimensional box of length $$L. $$Which equation gives the allowed energy levels?

Accepted Answer

$$E_n = \frac{n^2$ h^2$}{8mL^2$}$$

Question 18

Which of the following is a real-world application of nuclear fission?

Accepted Answer

Generation of electricity in nuclear power plants

Question 19

Which equation describes the relationship between the speed of light $$c$$, frequency $$f$$, and wavelength $$\lambda$$?

Accepted Answer

$$c = f \lambda$$

Question 20

Which of the following best describes the concept of isotopes?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Contemporary Physics Syllabus and Course Structure

Study Guide - Practice Questions

Study Guide - Flashcards