PHYS 2002 Exam 2 review

 The number of turns of an ideal solenoid is tripled, its length is doubled, and its cross-sectional area is kept constant. If the old inductance is L, what is the new inductance?

• 9L/2

• 3L/2

• 2L/3

• 9L/4

A transformer consists of a 300-turn primary coil and a 2000-turn secondary coil. If the current in the secondary coil is 9 A, what is the primary current?

• 1.35 A

• 35.4 A

• 60.0 A

• 25.0 A

The current I in a long wire is going up as shown, and increasing in magnitude. What is the direction of the induced current in the left loop and the right loop?

• L - CW

  R - CCW

• L - CCW

  R - CW

• L - CW

  R - CW

• L - CCW

  R - CCW

A uniform 4.50-T magnetic field is at a 30° angle relative to the normal of a circular wire loop with radius 18 cm. What is the magnetic flux passing through the loop?

• 0.25

• 0.65

• 0.80

• 0.40

A long straight wire and a rectangular conducting loop lie in the same plane as shown. If the current in the long wire is increasing, what is the direction of the net force exerted on the loop?

• Left

• Right

• Up

• Down