Physics Final Multiple Choice

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

follow a circular path

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

none of the above

a) one piece would be a magnetic north pole and the other would be a south pole

b) neither piece would be magnetic

c) each piece would be a smaller bar magnet with both a north and south poles and half of the magnetic strength of the original magnet

Two long parallel wires placed side by side on a horizontal table carry identical current strength straight toward you. from you pov the magnetic field at a point exactly between the two wires

is zero

Two long parallel wires are placed side by side on a horizontal surface. if the wires carry current in opposite directions

the wires push away from each other

When the current through a resistor is increased by a factor of 4, the power dissipated by the resistor

increased by a factor of 16

every minute, 120 C of charge flow through this cross section of the wire. the wire’s current is

2A

In a real battery that’s being used in a circuit, the terminal voltage is ____ the battery’s emf

less than

you double the voltage across a certain conductor and you observe the current increases three times. what can you conclude?

ohm’s law is not obeyed

When unequal resistors are connected in parallel in a circuit

the potential drip is always the same across each resistor

What are the units of potential difference

volt

a capacitor consists of a set of two parallel plates of area A separated by a distance s. The capacitor plates carry charges Q+ and Q-. If the separation between the plates is double, the potential difference between the plates will be

double

capacitors connected in parallel have the same

voltage

at the midpoint between these two equal but opposite charges

E points right; V=0

the charges +q, +Q, -Q are placed at the corners of an equilateral triangle. the net force on charge +q due to the other two charges is

horizontal to the right

If you bring a positively charged insulator near two uncharged metallic spheres that are in contact and then separate the spheres, the sphere on the right will have:

a positive charge

a block oscillating on a spring has a period of 3 sec. what is the period if the blocks mass is quadrupled?

6 sec

at the playground, two children are on identical swings. one child appears to be about twice as heavy as the other. if you pull them back together the same distance and release them to start them swinging, what will you notice about the oscillations of the two children?

both children swing with the same period

a wave pulse travels along a stretched sting at a speed of 200 cm/s. what will be the speed if the string’s mass is quadrupled but its length is unchanged.

100 cm/s