PHYS 1402 FINAL

The resistance of wire #1 is twice as high as that of wire #2

Copper wire #1 has a length L and a radius b. Copper wire #2 has a length 2L and a radius 2b. Which statement about the resistance across the ends of the wires is true?

having the same frequency and maintaining a constant phase difference

Two coherent light sources are characterized by

1/4 F

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude F due to the other. With time, charge gradually diminishes on both spheres by leaking off. When each of the spheres has lost half its initial charge, what will be the magnitude of the electrostatic force on each one?

q1 is negative and q2 is positive; the magnitude of q1 is less than the magnitude of q2

Two stationary point charges q1 and q2 are shown in the figure along with a sketch of some field lines representing the electric field produced by them. What can you deduce from the sketch?

converging lenses

Farsightedness can usually be corrected with

1/c

For an electromagnetic wave in free space having an electric field of amplitude E and a magnetic field of amplitude B, the ratio of B/E is equal to _____

D

Four point charges Q of equal magnitude and sign are arranged on three of the corners of the square of side d as shown in the figure. Which one of the arrows shown represents the net force acting on the charge at the upper right-hand corner of the square?

The equivalent resistance is more than the largest resistance

Four unequal resistors are connected in series with each other. Which one of the following statements is correct about this combination?

half your height

How tall must a plane mirror be in order for you to be able to see your full image in it?

a magnetic field

If a calculated quantity has units of N/A*m, that quantity could be _______

charge

If a quantity you calculated has units of A * s, what is that quantity?

The distance between the minima increases

If the distance between the slits in Young's two-slit experiment is decreased, which one of the following statements is true of the interference pattern?

does not change

If the electric field between the plates of a given air-filled capacitor is weakened by removing charge from the plates, the capacitance of that capacitor __________

decrease to one-half its original value

If the resistance in a constant voltage circuit is doubled, the power dissipated by that circuit will ________

each piece would in itself be a smaller bar magnet with both north and south poles

If you were to cut a small permanent bar magnet in half, _________

it becomes wider

In a single-slit diffraction experiment, the width of the slit through which light passes is reduced. What happens to the central bright fringe?

4*lambda

In the two-slit experiment, for the condition of bright fringes, the value of m = +4 corresponds to a path difference of

diverging lenses

Nearsightedness is usually corrected with ________

1. The current is exactly the same at points A, B, C and D 2. The potential at B is equal to the potential at C.

A 9-V battery is hooked up to two resistors in series using wires of negligible resistance. One has a resistance of 5 ohms, and the other has a resistance of 10 ohms. Several locations along the circuit are marked with letters, as shown in the figure. Which statements about this circuit are true?

It passes through the focal point of the mirror

A beam of light that is parallel to the principle axis is incident on a concave mirror. What happens to the reflected beam of light?

smaller than before

A capacitor C is connected in series with a resistor R across a battery and an open switch. If a second capacitor of capacitance 2C is connected in series with the first one, the time constant of the new RC circuit will be ________

follow a circular path

A charged particle is injected into a uniform magnetic field such that its velocity vector is perpendicular to the magnetic field lines. Ignoring the particles weight, the particle will _______

2R

A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field. If the particle were traveling twice as fast, the radius of the circular path would be _________

may experience a magnetic force, but its speed will not change

A charged particle that is moving in a static uniform magnetic field ________

totally reflected

The critical angle for a beam of light passing from water into air is 48.8°. This means that all light rays with an angle of incidence greater than this angle will be __________

The induced current flows counterclockwise

A coil lies flat on a tabletop in a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

4E

A coil of wire containing N turns is in an external magnetic field that is perpendicular to the plane of the coil and is steadily changing. Under these circumstances, an emf E is induced in the coil. If the rate of change of the magnetic field and the number of turns in the coil are now doubled (but nothing else changes), what will be the induced emf in the coil?

400 V

The electric potential at a distance of 4 m from a certain point charge is 200 V relative to infinity. What is the potential (relative to infinity) at at distance of 2 m from the same charge?

the image is inverted, and the mirror is concave

A negative magnification for a mirror means that

into the page

A positive charge is moving to the right and experiences an upward magnetic force, as shown in the figure. In which direction must the magnetic field have a component?

The charge on the capacitor after four time constants is about 98% of the maximum value

A resistor, an uncharged capacitor, a dc voltage source, and an open switch are all connected in series. The switch is closed at time t = 0 s. Which one of the following is a correct statement about this circuit?

It will double

A single-slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the wavelength is doubled?

2d

A small charged plastic ball is vertically above another charged small ball in a friction-less test tube as shown in the figure. The balls are in equilibrium a distance d apart. If the charge on each ball is doubled, the equilibrium distance between the balls in the test tube would become __________

Loop 2

The three loops of wire shown in the figure are all hanging in the same uniform magnetic field B that is perpendicular to the page and does not vary with time. Loop 1 swings back and forth like the bob in a pendulum, Loop 2 rotates about a vertical axis, and Loop 3 oscillates up and down at the end of a spring. Which loop (or loops) will have an emf induced in them?

B

Three equal charges +Q are at three of the corners of a square side d. A fourth charge +Q of equal magnitude is at the center of the square as shown in the figure. Which one of the arrows shown represents the net force acting on the charge at the center of the square?

trajectory Z

An electron is initially moving to the right when it enters a uniform electric field directed upwards, as shown in the figure. Which trajectory (X, Y, Z, or W) will the electron follow in the field?

path a

An electron is moving to the right, as shown in the figure. Suddenly it encounters a uniform magnetic field pointing out of the page. Which one of the three paths shown will it follow in the field?

Q

Three identical capacitors are connected in series across a potential source (battery). If a charge of Q flows into this combination of capacitors, how much charge does each capacitor carry?

1 is negative, 2 is neutral, and 3 is positive

Three particles travel through a region of space where the magnetic field is out of the page, as shown in the figure. What are the signs of the charges of these three particles?

from a to b

As shown in the figure, a metal bar is in contact with a pair of metal parallel rails. A steady uniform magnetic field B, perpendicular to the plane of the rails and pointing outward from the page, is present. The bar is in a downward motion with a velocity of magnitude v. The direction of the induced current through resistor R is ________

No current is induced

As shown in the figure, a metal bar is in contact with a pair of parallel rails and is in motion with an upward velocity of magnitude v. A uniform magnetic field is present, directed downward as shown. The direction of the induced current through the resistor R is _____________

The force on A is exactly equal to the force on B

Two tiny beads are 25 cm apart with no other charges or fields present. Bead A carries 10 micro-coulombs of charge and bead B carries 1 micro-coulomb. Which one of the following statements is true about the magnitudes of the electric forces on these beads?

1 mm/s

When current is flowing in an ordinary metal wire, the magnitude of the average velocity of the electrons is closest to _______

the power dissipated in each is the same

When different resistors are connected in parallel across an ideal battery, we can be certain that ______

1/sq-root(Eouo)

Which of the following expressions is the correct representation for the speed of light?

m = -di/do

Which of the following is a correct expression for magnification?

f = (1/2)R

Which of the following is correct for a concave mirror? (R is the radius of curvature)

v = fλ

Which of the following is the correct representation of the relationship between the speed of a wave (v), frequency of the wave (f), and its wavelength (lambda)?

radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays

Which of the following lists gives the correct order of the electromagnetic waves from longer wavelength to shorter wavelength?

1. an increase in the plate area and a decrease in the plate separation

Which of the following will increase the capacitance of a parallel-plate capacitor? (There could be more than one correct choice)

A

Which one of the arrows shown in the figure best represents the direction of the electric field between the two uniformly charged metal plates?

Young's double slit experiment

Which one of the following experiments is the justification for the wave theory of light?

sound waves

Which one of the following is NOT an electromagnetic wave?

sound waves

Which one of the following is not an electromagnetic wave?

virtual and upright

Which one of the following sets of characteristics describe the image formed by a plane mirror?

The north pole of a magnet points towards Earth's geographic north pole

Which one of the following statements is correct?

they all travel through space as the same speed

Which one of the following types of electromagnetic wave travels through space the fastest?

1. The electric potential is constant over the surfaces. 2. The electric field is perpendicular to the surface

Which statements must be true about the surface of a charged conductor in which no charge is moving? (There could be more than one correct choice.)

X is negative and Y is positive

X and Y are two initially uncharged metal spheres on insulating stands, and they are in contact with each other. A positively charged rod R is brought close to X as shown in part (a) of the figure. Sphere Y is now moved away from X, as shown in part (b). What are the final charge states of X and Y?

counterclockwise

a bar magnet is oriented above a copper ring, as shown in the figure. If the magnet is pulled upward, what is the direction of the current induced in the ring, as viewed from above?

energy

the electron-volt is a unit of ________