Physics 2 Final

What is a normal line? A. a line parallel to the boundary B. a vertical line separating two media C. a line perpendicular to the boundary between two media D. A line dividing incident ray from reflected or refracted ray E. Two of the above are possible

E. two are possible, both C and D

Consider 2 copper wires with circular cross sections and equal lengths. One wire has 3 times the diameter of the other. The thicker wire has ____ times the resistance of the thinner wire. A. 1/3 B. 1/9 C. 3 D. 9

1/9

Three resistors 50 ohm, 120 ohm and 180 ohm are connected in series in a circuit. What is the equivalent resistance of this combination of resistors? A. 250 ohm B. 200 ohm C. 350 ohm D. 120 ohm E. 29 ohm

C. 350 Req= R1 + R2 + R3

The x and y components of a force are +3 N and +4 N respectively. What is the magnitude of this force? A. 7 N B. 5 N C. 1 N D. 12 N E. 25 N

5 N

Given the following equation describing the motion of an object: x = A cos ((2pi/T)*t) Which of the following statements is true A. the object is at its maximum amplitude at t=0 B. The object is at x=0 at t = 0 C. The object is halfway between its maximum and minimum displacement

A

Which of the following represents a milli? A. 1/1000 B. 1000 C. 100 D. 1/100 E. 10^-6

A

The index of refraction of a type of glass is 1.50 and the index of refraction of water is 1.33. If light enters water from this glass, the angle of refraction will be: A. greater than the angle of incidence B. equal to the angle of incidence C. less than the angle of incidence

A What equation do you use for this?

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 form above, what is the sense of the induced current in this coil as the field fades? A. the induced current flows counterclockwise B. the induced current flows clockwise C. there is no induced current in this coil D. the current flows clockwise initially, and then it flows CCW before stopping

A not really sure why

Three resistors, 4 ohm, 8 ohm, 16 ohm, are connected in parallel in a circuit. What is the equivalent resistance of this combination of resistors? A. 2.3 ohm B. 10 ohm C. 30 ohm D. 2.9 ohm E. 0.34 ohm

A. 2.3 ohm Req= (1/R1 + 1/R2 + 1/R3) ^-1

A concave mirror has a focal lenght of magnitdue 12 cm. An object is palcd in front of this mirror at a point 8 cm from the face of teh mirror. The image will be A. real and enlarged B. upright and reduced C. upright and enlarged D. real and inverted E. virtual and reduced.

C. upright and enlarged given: s and f makeup a h determine s'= (1/f - 1/s) ^-1 determine h'= -s'/s * h

The positive terminal of a battery is called a/an A. anode B. cathode C. anti-node D. positrode E. conductor

A. anode

What magnetic pole is near the earths south geographic pole? A. magnetic N B. Magnetic S C. both a and B possible

A. magnetic N

Outside of a bar magnet, the magnetic field lines are drawn to go into the ____ magnetic pole A. south B. north C. both of the above D. none of the above

A. south

Which one of the following is a symbol for current? A. A B. I C. C D. V E. R

B

A charge +q is a distance d from a charge -Q. If the distance between them is decreased how would that affect the electrical potential energy of the charges? A. it will be larger B. it will be smaller C. it will remain the same

B it will be smaller

The radius of curvature of a spherical convex mirror is 52 cm. What is the focal length? A. +26 cm B. -26 cm C. +52 cm D. -52 cm E. +104 cm

B. -26 cm f= -r/2 That equation is a maybe. Is it negative because its to the left of the mirror?

How much energy does a 100 W light bult use in 8 hours? A. 0.0080 kWh B. 0.80 kWh C. 13 kWh D. 800 kWh

B. 0.80 kWh (100*8)* 10^3

Which one is fundamental SI unit for electricity? A. Coulomb B. Volt C. Ampere D. ohm E watt

C. ampere

What is the prefix n used for? A. a hundreths B. a billionth C. a trillionth D. a thousandth E. a millionth

B. a billionth

A proton traveling horizontally due south in a region that contains only a magnetic field experiences a vertically upward force. What is the direction of the magnetic field? A. north B. east C. south D. west E. down

B. east use RH rule thumb (velocity) palm (force) Fingers (field)

A 2 m long metal wire is formed into a square and placed in the horizontal xy plane. A uniform magnetic field is oriented at 30 degree above the horizontal with a strength of 0.344 T. What ist eh magnetic flux through the square due to this field? A. 0.0745 T*m^2 B. 0.172 T*m^2 C. 0.0430 T*m^2 D. 0.298 T*m^2

C

A charge +Q is at the origin and a second charge +Q is located at x=d and y=-d. What is the direction of the force on the charge at its origin? A. along the +x axis B. kQ^2/d^2 C. along a direction 45 degrees CW from -x axis D. along a direction 45 degrees CW from +x axis E. kQ^2/2d^2

C

Which one is a unit for magnetic flux? A. N/ (A*m) B. T/m^2 C. J/C D. Wb/m^2 E. J/A * m

C

If the magnification of a mirror or lens is negative, it means that A. the image is smaller than the object B. the image is inverted and smaller than the object C. the image is inverted D. the object is farther from the mirror (or lens) than the image E. the image is farther from the mirror (or lens) than the object

C its flipped below the x axis

A transformer is a device used to A. transform an alternating current into a direct current B. transform a direct current into an alternating current C. increase or decrease an ac voltage D. increase or decrease a dc voltage

C increase or decrease an ac voltage

The image distance s' is the distance of the A. object to the image B. object to the mirror C. Image to the mirror D. image from the focal point E. object from the focal point

C.

A total of 2.0 * 10^13 electrons pass a given point in a wire in 15 s. What is the current in the wire? A. 1.3 mA B. 1.3 A C. 0.21 MuA D. 3.2 MuA

C. 0.21 MuA I = (Ne)/change in time

What type of a lens can produce a virtual image? A. convex lens B. concave lens C. both A and B D. none of the above because you need a convex mirror for it

C. Both A and B

A conducting wire cooled down to very low temperature (10-20 K) loses its resistance to flow of electrical current completely. This conductor is called A. transistor B. dielectric C. superconductor D. semiconductor

C. superconductor

When a light bulb is connected to a 4.5 V battery, a current of 12 mA passes through the bulb filament. What is the resistance of the filament? A. 54 omh B. 2.67 ohm C. .540 ohm D. 3.8 * 10 ^ 5 ohm E. 375 ohm

E. 375 ohm

A simple pendulum (mass m and length L) is released and oscillates back and forth. The pendulum has its least potential energy when A.) it is moving the fastest B.) it is passing through its lowest poistion C.) it has its greatest kinetic energy D.) all of the above

D

When an object is 12 cm in front of a concave mirror, the image is 3.0 cm in front of the mirror, what is the focal length of the mirror? A. -0.25 cm B. 15 cm C. 4.0 cm D. 2.4 cm E. -1.3 cm

D s=12 s'=3 f= (1/s + 1/s')^-1

A long straight wire is carrying a current of 5 A to the left. The point P is 0.040 m below the wire. What is the direction of the magnetic field at point P due to the current in the wire? A. to the right of page B. to the left of page C. toward bottom of the page D. into the plane of the page E. out of the plane of the page

E. Out of the page use RH rule

The magnetic force on a current carrying wire in a magnetic field is the strongest when A. the current is in the direction of the magnetic field lines B. the current is in the direction opposite to the magnetic field lines C. the current is at a 180 degree angle with respect to the magnetic field lines D. the current is perpendicular to the magnetic field lines E. the current is at a 0 degree angle with respect to the magnetic field lines

D. both c and e the force would equal 0

What is the letter prefix that represents a trillion? A. p B. G C. M D. T E. N

D. T

You have a horseshoe magnet facing down towards the table. The left end is a north magnetic pole and teh right end is a south magnetic pole. When the switch is closed in the circuit, which way will the wire between the poles of the horseshoe magnet initially deflect? A. to the right B. to the left. C. upward. D. downward

D. donward

A single turn loop of wire having a resistance of 8 ohm and a cross sectional area 200 cm^2 is perpendicular to a uniform magnetic field that increases steadily from 0.200 T to 2.800 T in 2.20 seconds. What is the magnitude of the induced current? A. 2.95 A B. 3.18 A C. 0 A D. 3.18 mA E. 2.95 mA

E

A charge Q exerts a 1.2 N force on another charge q. If the distance between the charges is halved, what is the magnitude of the force exerted on Q by q? A. 0.30 N B. 0.60 N C. 2.4 N D. 3.6 N E. 4.8 N

E 4.8 N

What does the slope in a current v. potential graph represent? A. power B. resistivity C. 1/resistivity D. resistance E. 1/resistance

E. 1/resistance

How many centigrams in a kilogram? A. 10^2 B. 10^4 C. 10^6 D. 10^-4 E. 10^5

E. 10^5

Which of the following is a unit for # of oscillations per unit time: A. seconds B. f C. hertz D. radians E. radians -1

hertz