Q: A laser pointer emits light at $$650\ \mathrm{nm}. $$What is the energy of a single photon? (Use $$E = \frac{hc}{\lambda}$$, $$h = 6.63 \times 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$3.06 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: A $$1.0\ \mathrm{m}$$ long solenoid has 1000 turns and carries a current of $$2.0\ \mathrm{A}. $$What is the magnitude of the magnetic field inside the solenoid? (Use $$B = \mu_0$ n I$$, $$n = N/L$$, $$\mu_0$ = 4\pi \times 10$$^{-7}$$\ \mathrm{T \cdot m/A})$$

$$2.51 \times 10$$^{-3}$$\ \mathrm{T}$$

Question 1

A beam of light passes from air into glass at an angle of incidence of $$30^\circ. If $$the refractive index of glass is $$n = 1.5$$, what is the angle of refraction inside the glass? (Use Snell's Law: $$n_1$$ \sin \$$theta_1$$ = $$n_2$$ \sin \$$theta_2)$$

Accepted Answer

$$19.5^\circ$$

Question 2

A double-slit experiment uses light of wavelength $$\lambda = 600\ \mathrm{nm}$$ and slit separation $$d = 0.2\ \mathrm{mm}. $$What is the angular position $$	heta of $$the first-order maximum? (Use $$d \sin 	heta = m \lambda$$ for maxima)

Accepted Answer

$$0.172^\circ$$

Question 3

A thin lens has a focal length $$f = 10\ \mathrm{cm}. An $$object is placed $$15\ \mathrm{cm}$$ from the lens. Where is the image formed? (Use the lens equation: $$\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i})$$

Accepted Answer

$$30\ \mathrm{cm}$$ \, on the opposite side of the lens

Question 4

A microscope uses an objective lens of focal length $$4\ \mathrm{mm}$$ and an eyepiece of focal length $$25\ \mathrm{mm}. If $$the tube length is $$160\ \mathrm{mm}$$, what is the approximate angular magnification of the microscope? (Use $$M = \left(\frac{L}{f_o}\right) \left(\frac{25\ \mathrm{cm}}{f_e}\right)$$, where $$L is $$the tube length, $$f_o is $$the objective focal length, and $$f_e is $$the eyepiece focal length.)

Accepted Answer

$$400$$

Question 5

A soap film (index $$n = 1.33) in $$air is illuminated with white light at normal incidence. What is the minimum nonzero thickness for constructive interference for light of wavelength $$600\ \mathrm{nm}$$? (Use $$2 n t = m \lambda$$, $$m=1$$ for first order.)

Accepted Answer

$$226\ \mathrm{nm}$$

Question 6

Which of the following best describes the photoelectric effect as explained by Einstein?

Accepted Answer

Light consists of photons, and electrons are ejected from a metal only if the photon energy $$E = h 
u$$ exceeds the work function.

Question 7

A parallel-plate capacitor with plate area $$A$$ and separation $$d is $$connected to a battery of voltage $$V. $$What is the energy stored in the capacitor? (Use $$U = \frac{1}{2} C V^2$, C$$ = \$$varepsilon_0$$ \frac{A}{d}$$)

Accepted Answer

$$U = \frac{1}{2} \$$varepsilon_0$$ \frac{A}{d} V^2$

Question 8

A point charge $$q is $$placed at the center of a spherical conducting shell of inner radius $$a$$ and outer radius $$b. $$What is the electric field at a distance $$r$$ such that $$a \u003c r \u003c b$$?

Accepted Answer

$$E = 0$$

Question 9

A $$10\ \mu\mathrm{F}$$ capacitor is charged to $$12\ \mathrm{V}$$ and then connected across a $$2\ \mathrm{k}\Omega$$ resistor. What is the time constant $$	au of $$the resulting RC circuit?

Accepted Answer

$$0.02\ \mathrm{s}$$

Question 10

A long straight wire carries a current $$I. $$What is the magnitude of the magnetic field at a distance $$r$$ from the wire? (Use Ampère's Law: $$B = \frac{\mu_0$ I}{2 \pi r})$$

Accepted Answer

$$B = \frac{\mu_0$ I}{2 \pi r}$$

Question 11

A proton is moving perpendicular to a uniform magnetic field $$B$$ with speed $$v. $$What is the radius of its circular path? (Use $$r = \frac{mv}{qB})$$

Accepted Answer

$$r = \frac{mv}{qB}$$

Question 12

A parallel beam of white light passes through a diffraction grating with 5000 lines/cm. What is the angular separation between the first-order maxima for wavelengths $$400\ \mathrm{nm}$$ and $$700\ \mathrm{nm}$$? (Use $$d \sin 	heta = m \lambda)$$

Accepted Answer

$$1.72^\circ$$

Question 13

Which of the following statements about Gauss's Law is correct?

Accepted Answer

The net electric flux through any closed surface is proportional to the total charge enclosed by the surface.

Question 14

A charged particle is accelerated from rest through a potential difference $$V. $$What is its final kinetic energy? (Use $$K = qV)$$

Accepted Answer

$$K = qV$$

Question 15

A wire loop of area $$A is $$placed in a time-varying magnetic field $$B(t) = B_0$ \cos(\omega t). $$What is the induced emf in the loop? (Use Faraday's Law: $$\mathcal{E} = -\frac{d\Phi}{dt}$$, $$\Phi = BA)$$

Accepted Answer

$$\mathcal{E} = A B_0$ \omega \sin(\omega t)$$

Question 16

A $$100\ \Omega$$ resistor and a $$200\ \Omega$$ resistor are connected in parallel across a $$12\ \mathrm{V}$$ battery. What is the total current supplied by the battery?

Accepted Answer

$$0.18\ \mathrm{A}$$

Question 17

Which of the following best explains why the sky appears blue during the day?

Accepted Answer

Shorter wavelengths of light are scattered more efficiently by atmospheric molecules (Rayleigh scattering).

Question 18

A laser pointer emits light at $$650\ \mathrm{nm}. $$What is the energy of a single photon? (Use $$E = \frac{hc}{\lambda}$$, $$h = 6.63 	imes 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$3.06 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 19

A $$1.0\ \mathrm{m}$$ long solenoid has 1000 turns and carries a current of $$2.0\ \mathrm{A}. $$What is the magnitude of the magnetic field inside the solenoid? (Use $$B = \mu_0$ n I$$, $$n = N/L$$, $$\mu_0$ = 4\pi 	imes 10$$^{-7}$$\ \mathrm{T \cdot m/A})$$

Accepted Answer

$$2.51 	imes 10$$^{-3}$$\ \mathrm{T}$$

Physics 1220: Physics for Physical & Applied Sciences II – Course Syllabus and Study Guide

Study Guide - Practice Questions

Study Guide - Flashcards