E&M Exam 2

A positive charge is moving at constant v directly toward P. The magnetic field that the point charge produces at P is?

zero

A long wire along y carries I in + y. A point charge moves along the + x-axis, what is the direction of the B force?

positive y

Two charges move side by side in the same directio. What is the

direction of the force upper exerts on lower?

toward the upper point charge (the force is attractive)

Under what circumstances the total magnetic ;ux through a closed surface is positive?

none of the above

When a charged particle moves through a magnetic Aeld, the trajectory of the particle at a given point is

any of A., B., or C.

circular loop of wire carries a current and is placed in a region of uniform B, the net magnetic force on the loop is

zero

circular loop of wire carries a current and is placed in a region of uniform B, the net magnetic torque on the loop

orients the loop so that its plane is perpendicular to B

When a charged particle moves through a magnetic field, the direction of the magnetic force is

perpendicular to the magnetic field

A beam of electrons is coming out of the screen in the presence of a magnet as show in the picture. direction of force?

left

The picture shows a positively charged particle moving in the xz plane with B=Bz. which direction the induced F points

negative y

To simultaneously measure the current in the resistor and the voltage across a resistor you place:

an ammeter in series and a voltmeter in parallel.

3 bulbs are connected in series as shown in the @gure. V =120 V. Across which bulb is the voltage drop largest?

60 W bulb

3 bulbs are connected in series as shown in the @gure. V =120 V. Which bulb glows brighter?

the 60 W

You slide a slab of dielectric between a capacitor. The charges on the plates remain constant. What happens to V?

The potential difference decreases

We slide a dielectric again, maintaining the charge constant. What happens to the energy stored in the capacitor?

decreases

Capacitor holds charge +Q and -Q. We double the charge two +2Q and -2Q, what is the new capacitance C?

same

we double the capacitance of a parallel plate capacitor while

maintaining the charges. What happens to the potential Vab

1/2 X smaller

Two wires of different diameter are joined. When electrons move from the large to the small one how does Vd change?

drift speed increases

We apply a voltage V to a superconductor and then remove it so V=0. what happens to the induced current?

Stays the same

Which of the two arrangements shown has the smaller equivalent resistance between points a and b?

The parallel arrangement (b)

Three light bulbs are connected in parallel, with V =120 V. Which bulb has the largest voltage drop?

The voltage drop across all three bulbs is the same

Three identical incandescent light bulbs are connected to a source of emf as shown. Which bulb glows the brightest?

light bulb A glows the brightest

What is the direction of the magnetic field induced by the current

in the figure?

into the plane of the figure

All currents in the figure have the same magnitude. Which patch (a, b, c, or d) will carry no current?

a and c