final exam multiple choice

Question 1

e- initially moving to right and enters an electric field directed up, which pathway will it follow?

Answer 1

trajectory z (bottom one)

Question 2

which of the following increases the capacitance of a parallel plate capacitor

Answer 2

-decrease the separation between plates
-add dielectric material between

Question 3

an ideal parallel plate capacitor has capacitance C. what happens if the distance between plates is halved and area is doubled

Answer 3

4C

Question 4

when a current flows through an ionic liquid such as salty water the moving charges are

Answer 4

both positive and negative ions

Question 5

battery charges a parallel plate capacitor fully and is then removed, the plates are then slowly pulled apart, what happens to the potential difference as they are being separated

Answer 5

it decreases

Question 6

you are given a copper bar of dimensions of 3cmx5cmx8cm and asked to attach leads, to achieve smallest resistance you attach leads to

Answer 6

3cm x 5cm

Question 7

as more resistors are added in series to constant voltage the power supplied by the source…

Answer 7

increases

Question 8

charged particle entered into a uniform mag field where velocity is perpendicular to the mag field lines, the particle will

Answer 8

follow a circular path

Question 9

a horizontal wire carries a current straight towards you, from your pov the mag field caused by the current…

Answer 9

circles the wire in a counter-clockwise direction

Question 10

in the figure the bar magnet moves away from the solenoid, direction of the induced current through the resistor is

Answer 10

from a to b

Question 11

in the figure one end of a metal bar is in contact with circular rail, mag field is present, when bar rotates in clockwise direction the induced current in the resistor is from

Answer 11

b to a

Question 12

in double slit interference…. greates seperation between the slits you would use

Answer 12

red light

Question 13

a single-slit diffraction pattern is formed on distant screen, assuming the angles are small, what factor will the central bright spot change if the wavelength is doubled

Answer 13

it will double

Question 14

when a beam of light travels in air and enters glass having a refractive index of 3/2, its wavelength

Answer 14

is reduced to 2/3 its original value

Question 15

convex lens has a focal length f if an object located at infinity, the image formed is located at a distance from the lens

Answer 15

of f

Question 16

the image formed by a single concave lens

Answer 16

is always real

Question 17

a critical angle for a beam of light passing from water into air is air 48.8 degrees this means that all light rays with an angle of incidence in the water is greater than 48.8 will be

Answer 17

totally reflected

Question 18

which of the following terms describes lenses that are thicker at the center than at the edges

Answer 18

converging, convex lens

Question 19

which of the follwoing statements about the image formed by a single diverging lens are true

Answer 19

-always virtual
-always upright

Question 20

a negative magnification for a mirror means that

Answer 20

the image is inverted and the mirror is concave

Question 21

single concave spherical mirrors produce images that

Answer 21

could be smaller, larger, or the same size depending on the placement of the object

Question 22

infared and x ryas have different

Answer 22

frequencies and wavelengths

Question 23

addition of two waves producing a stronger wave is called

Answer 23

constructive interference

Question 24

shine laser through a double slit, what would you so to increase the distance

Answer 24

-move slits further from wall
-decrease spacing between slits
-use a longer wavelength

Question 25

radioactive decay from most to least dangerous

Answer 25

gamma, beta -, beta +, alpha

Question 26

weakest nuclear force is the

Answer 26

gravitational force

Question 27

plastic rod given a negative charge by rubbing the right end with wool, the negative charge in the rod is…

Answer 27

evenly distributed

Question 28

the job of a bettery is to provide

Answer 28

constant voltage

Question 29

if the rod that was rubbed with wool is now held near a conductive sphere that is grouneded, the sphere has a ______ charge

Answer 29

positive

Question 30

a proton is released from rest in a uniform electric field, the proton ill move….

Answer 30

in the same direction as the field

Question 31

the protons kinetic energy will _____ and its electric potential will ______ when proton is released in a uniform electric field.

Answer 31

increase, decrease

Question 32

the mag force on a current carrying wire in a mag field is always ______ to the current and _____ to the mag field

Answer 32

perpendicular, perpendicular

Question 33

compared to the force on the electron, the magnitude of the magnetic force on the proton is ______, and the direction of the mag force on the proton is _____-

Answer 33

the same, opposite

Question 34

the particles will both travel in circular paths, the radius of the protons path will be _____ the radius of the electrons path

Answer 34

greater than

Question 35

if two light bulbs are wired in series what to the current if one bulb burns out

Answer 35

there will be no current

Question 36

metal bar in contact with parallel rails and the direction of the induced current is

Answer 36

no current is induced