Electromagnetic Induction Ch. 29

A circular loop of wire is in a region of spatially uniform magnetic field. The magnetic field is directed into the plane of the figure. If the magnetic field magnitude is constant,

• the induced emf is clockwise.

• the induced emf is counterclockwise.

• the induced emf is zero

• The answer depends on the strength of the field.

A circular loop of wire is in a region of spatially uniform magnetic field. The magnetic field is directed into the plane of the figure. If the magnetic field magnitude is increasing,

• the induced emf is clockwise.

• the induced emf is counterclockwise.

• the induced emf is zero.

• The answer depends on the strength of the field.

A circular loop of wire is placed next to a long straight wire. The current I in the long straight wire is increasing. What current does this induce in the circular loop?

• a clockwise current

• a counterclockwise current

• zero current

• not enough information given to decide

A circular loop of wire is placed next to a long straight wire. The current I in the long straight wire is increasing. The circular loop will be

• attracted to the long wire

• repelled away from the long wire

• neither attract nor repel

• not enough information given to decide

A circular loop of wire is placed next to a long straight wire. The current I in the long straight wire is decreasing. The circular loop will be

• attracted to the long wire and the induced current is clockwise

• repelled away from the long wire and the induced current is counterclockwise

• attracted to the long wire and the induced current is counterclockwise

• repelled away from the long wire and the induced current is clockwise

A flexible loop of wire lies in a uniform magnetic field of magnitude B directed into the plane of the picture. The loop is pulled as shown, reducing its area. The induced current

• flows downward through resistor R and is proportional to B.

• flows upward through resistor R and is proportional to B.

• flows downward through resistor R and is proportional to B 2.

• none of the above

The rectangular loop of wire is being moved to the right at constant velocity. A constant current I flows in the long straight wire in the direction shown. The current induced in the loop is

• clockwise and proportional to I.

• counterclockwise and proportional to I.

• clockwise and proportional to I2

• counterclockwise and proportional to I2.

• zero

The loop of wire is being moved to the right at constant velocity. A constant current I flows in the long straight wire in the direction shown. The current induced in the loop is

• clockwise and proportional to I.

• counterclockwise and proportional to I

• clockwise and proportional to I2.

• counterclockwise and proportional to I2.

The drawing shows the uniform magnetic field inside a long, straight solenoid. The field is directed into the plane of the drawing, and is increasing. What is the direction of the electric force on a positive point charge placed at point a ?

• to the left

• to the right

• straight up

• straight down

The drawing shows the uniform magnetic field inside a long, straight solenoid. The field is directed into the plane of the drawing, and is increasing. What is the direction of the electric force on a positive point charge placed at point c (at the center of the solenoid)?

• to the right

• straight up

• misleading question — the electric force at this point is zero

• straight d