AJ

When would two waves be aligned peak to peak?

PICK one BELOW

a

When they are not in phase, have different frequencies, and are propagating along the same line.

b

When they are in phase, have different frequencies, and are propagating along the same line.

c

When they are not in phase, but have the same frequency and are propagating along the same line.

d

When they are in phase, have the same frequency, and are propagating along the same line.

Why would it most likely be difficult to observe quantized orbital states for satellites orbiting the earth?

a At the atomic level, the orbital states do exist but are too closely spaced for us to see.

b At the atomic level, the orbital states do not exist for the electrons revolving around the nucleus.

c On a macroscopic level, we cannot control the amount of energy that we give to an artificial satellite and thus control its orbital altitude.

d On a macroscopic level, we cannot control the amount of energy that we give to an artificial satellite but we can control its orbital altitude.

One of the decay products of 238U

238 U is 226Ra . A rock originally contained 238U , which has a half-life of 4.5×10^ 9 yr, and 226Ra, which has a half-life of 1,600 yr. After 5×10^9 yr, which isotopes would you expect to be present in significant amounts in the rock?

Now choose from one of the following optionsWhy?

a 226Ra but not 238U

b Neither 238U nor 226Ra

c 238U but not 226Ra

dBoth 238U and 226Ra

A wire loop lies in the plane of the page and a magnetic field goes from right to left, also in the plane of the page. What is the magnetic flux through the loop?

a The magnetic flux through the loop is zero.

b The magnetic flux through the loop is infinite.

c The magnetic flux through the loop is finite but not zero.

d The magnetic flux through the loop varies irregularly.

a

The path of the light remains the same.

b

The path of the light becomes circular.

c

The path of the light becomes curved.

d

The path of the light changes.

An electron in an atom has angular momentum projection quantum number ml=2

m 1 = 2 . What is the smallest possible value for its angular momentum quantum number 1 ?

-2

0

1

2

Which of the following properties of an electron in an atom can be expressed with quantum numbers?

1 energy

2 linear momentum

3 angular momentum

4 spin

A 500-nm beam of light passing through a diffraction grating creates its second band of constructive interference at an angle of 1.50°. How far apart are the slits in the grating?

38,200 nm

19,100 nm

667 nm

333 nm

Multiple Choice

A. Later, under the influence of T-helper cells, IgM-secreting plasma cells may stop producing and secreting IgM in favor of another antibody class, usually IgD.

B. Pentameric IgM serves as the B-cell receptor for antigen, and monomeric IgM is the first type of antibody secreted after B-cell activation.

C.Class switching occurs when a cell secreting IgM changes the constant region of its antibody molecules, producing a different antibody class (IgG, IgA, or IgE).

A. Binding of antibody to biologically active materials (such as bacteria, toxins, or viruses) causes their inactivation or neutralization.

B. Cross-linking of epitopes on antigens with antibody does not occur.  C. Clonal selection is the process by which microorganisms or other foreign particles are coated with antibody or complement and thus prepared for “recognition” and ingestion by phagocytic cells.D. When the immune complex involves the cross-linking of cells, a precipitin reaction occurs; these immune complexes are more rapidly phagocytosed than free antigens.

What happens to the momentum of a photon upon recoiling from an electron?

a The momentum of the photon increases.

b The momentum of the photon decreases.

c The momentum of the photon remains constant, while energy of the photon decreases.

A lightbulb is wired to a variable resistor. What will happen to the color spectrum emitted by the bulb as the resistance of the circuit is increased?

a.The bulb will emit greener light.

b.The bulb will emit bluer light.

c.The bulb will emit more ultraviolet light.

d.The bulb will emit redder light.

a.Fewer optical devices are required in the microscopes.

b There is a higher contrast in the images that are produced.

c The light sources that are used are less expensive.

d The images that are produced are brighter.

A laser beam is transmitted from Earth toward the Moon. Should the diameter of the beam be increased or decreased in order to decrease spreading out of the beam?

a. INCREASE

b. DECREASE

a The wavelets from the slit travel parallel to each other.

b The wavelets from the slit arrive in different phases.

Will a beam of light shining through a 1-mm hole behave any differently than a beam of light that is 1mm wide as it leaves its source? Explain.

Now choose from one of the following optionsWhy?

a Yes, the beam passing through the hole will spread out as it travels, because it is diffracted by the edges of the hole, whereas the 1-mm beam, which encounters no diffracting obstacle, will not spread out.

b Yes, the beam passing through the hole will be made “more parallel” by passing through the hole, and so will not spread out as it travels, whereas the unaltered wavefronts of the 1-mm will cause the beam to spread out as it travels.

c No, both beams will remain the same width as they travel, and they will not spread out.

d No, both beams will spread out as they travel.

How does a medium’s index of refraction affect wavelength?

a

The higher the index of refraction, the longer the wavelength in the medium.

b

The higher the index of refraction, the shorter the wavelength in the medium.

A person timing the moonrise looks at her watch and then at the rising moon. Describe what happened inside her eyes that allowed her to see her watch clearly one second and then see the moon clearly.

a.The shape of the lens was changed by the sclera, and thus its focal length was also changed, so that each of the images focused on the retina.

b.The shape of the lens was changed by the choroid, and thus its focal length was also changed, so that each of the images focused on the retina.

c.The shape of the lens was changed by the iris, and thus its focal length was also changed, so that each of the images focused on the retina.

d.The shape of the lens was changed by the muscles, and thus its focal length was also changed, so that each of the images focused on the retina.