Multiple Choice Physics Final

A charged insulator and an uncharged metal will…

attract each other electrically

A charge +𝑄𝑄 and −2𝑄𝑄 are held a small distance away from one another as shown in the figures below. The arrows in each figure represent the size and direction of the electric force caused by one of the charges acting on the other. Which figure best represents the size and direction of the forces acting on each charge as they interact?

None of these figures are correct

A tiny charged pellet of mass 𝑚𝑚 is suspended at rest between two horizontal charged metallic plates. The lower plate has a positive charge and the upper plate has a negative charge. Which statement in the choices listed below is a false statement?

The pellet is negatively charged.

In the figure, a region of electric field is shown. Four indicated points in space (A-D) in the region of the electric field are also shown. Which pair of points has the smallest potential difference between the

Points B and C

An air-filled capacitor with plate area 𝐴𝐴 and plate spacing 𝜋𝜋 is connected to a battery with terminal voltage 𝑉𝑉. The capacitor is fully charged, storing charge 𝑄𝑄. If the plates are stretched out to cover an area of 2𝐴𝐴 using insulating materials without disturbing the connection to the battery, how much charge is now stored in the capacitor?

2Q

Two wires are made of the same material. One wire has twice the diameter of the other. How does the resistance of the narrow wire compare to that of the wide wire?

The narrow wire’s four times as large.

Which bulb ion the circuit shown below dissipates the most power when the switch is closed?

Bulb D

Consider the four statements below. Which one of the statements is a true statement?

To measure current passing through a circuit element, the ammeter should be connected in series with that circuit element

A complex circuit is shown in the figure. A student assigned the current directions as indicated. However, there is at least one current that is drawn incorrectly. This can be fixed by changing a single current direction in the circuit. Changing which one current’s direction would result in all junctions obeying Kirchhoff’s Junction rule?

Current I₁

An uncharged capacitor is connected in series with a resistor, a DC battery, and an open switch. At time t=0, the switch is closed. Which of the graphs below describes the current, I, through thee resistor as a function of time t?

A positively charged rod is brought close to a neutral compass needle pivoted about its center shown in the figure. Does the needle rotate?

No, not at all.

A current carrying wire is oriented perpendicular to the page, carrying its current out of the page. A magnetic field is oriented parallel to the page, downward. What is the direction of the force acting on this current carrying wire?

Right

A coil of wire, shown in cross section, is shown in the figure. Four locations are indicated in the figure, A through D. Which of them best represents the approximate location of the south pole of the coil

Point C

An electron moves in the region near a current carrying wire. The current is being carried toward the top of the page, and the electron moves directly toward the wire from the left side. This is shown in the figure. What is the direction of deflection, if any, of the electron?

Up

If a compass is placed above a current-carrying wire, the needle will line up with the field of the wire. Which of the views below shows the correct orientation of the needle for the noted current direction? (Darker side of the compass is the north pole.

Compass C

The conducting loop shown in the figure is slid in between the poles of a permanent magnet. During this time, what is the direction of the current in the leftmost side of the coil, marked A in the figure?

Into the page

A single circular coil of wire connected to a galvanometer is lying flat on the table, as you view it from above. There is a magnetic field in this region that pokes perpendicular to the table (in such a way that the field lines go through the loop). The magnetic field is reduced to zero over a period of 20 seconds, and a clockwise current is measured using a galvanometer. The magnetic field is then increased back to its original value over a period of 10 seconds. What would the galvanometer read?

The measured current would be larger, but in the opposite direction.

The figure shows two waves propagating with the same speed. Compared to the lower wave, the upper wave has a greater….

amplitude and wave number

For the wave shown in the figure below, the wavelength of the wave is _____.

Unable to tell determined from the information given

Which of the following waves require a physical medium through which to travel?

sound

You have three materials that are transparent to light: gasoline (n = 1.4), lab-grown diamond (n = 2.41), and ice (n = 1.31). In which material does light travel the fastest?

Ice

Along what axis does a plane mirror cause a reversal?

Front/Back (z-axis)

A ray of light that follows the path shown in the figure as it reaches the boundary between two transparent materials. What can

you conclude about the relative indices of refraction of these two materia

n₁ > n₂

You are observing your face in a cosmetic mirror. You note that your image is upright and enlarged. What kind of mirror created this image? Where is this image

A concave mirror. The image is behind the surface of the mirror.

Which of these is not a primary ray for a mirror?

A ray that aims at the center of the mirror and is unaffected, continuing in a straight line after interacting with the mirror.

If an object lies outside the focal point of a converging lens, which of the following statements about the image formed by this lens is true?

The image could be reduced or magnified, depending on how far the object is past the focal point.

Everyone’s vision is compromised underwater without goggles, but some can see a bit better than others. Which of the following individuals would have the clearest underwater vision?

A person with myopia

Two sources of coherent radio waves broadcasting in phase are located as shown below (the starbursts). Each grid square is 1.0 m square, and the radio sources broadcast at λ = 3.0 m. At location P, which of the following best characterizes the interference?

somewhere between constructive and destructive

Light passes through a 10-μm wide slit and is viewed on a screen 1m behind the slit. If the width of the slit is widened, the band of light will

become narrower

A particular thin plastic coating on your windshield helps prevent reflections of sunlight into other driver’s eyes. The index of the coating is 𝑠𝑠𝑓𝑓 = 1.42, while the glass below it has an index of 𝑠𝑠𝑔𝑔 = 1.55. Which equation would you use to determine the wavelength of light that is most strongly reduced by this coating?

2t= (m +1/2)𝜆/n_f