1. The average speed at which charge carriers in an electrical current move through a conductor is called the

a. drift velocity

b. current velocity

c. instantaneous velocity.

d. root-mean-square velocity.

2. A resistance irreversibly converts electrical energy into

a. mechanical work.

b. potential energy.

c. chemical energy.

d. heat energy.

3. An electrical circuit in which the voltage across every circuit element must be the same is called a

a. series circuit.

b. parallel circuit.

c. simple circuit.

d. ohmic circuit.

4. A unit commonly used to measure electrical energy is the

a. ampere-second.

b. kilowatt-hour.

c. volt-second.

d. coulomb per second.

5. What potential difference is required across a 6.5 Ohms resistor for 370 C of charge to flow through it in 2.5 minutes?

a. 0.02 V

b. 16 V

c. 22 V

d. 55 V

6. What is the equivalent resistance of a 22 Ohms, a 40 Ohms, and a 32 Ohms resistor connected in series?

a. 14 Ohms

b. 62 Ohms

c. 85 Ohms

d. 94 Ohms

7. If the relationship between voltage and current for a material is not linear, the material is said to be:

a. non-amperian

b. non-conducting

c. non-ohmic

d. indeterminate

8. As more resistors are added in parallel to a constant voltage source, the power supplied by the source

a. increases.

b. decreases.

c. does not vary.

d. may either increase or decrease depending upon the value of the resistors.

9. Two resistors have the same power dissipated in them. The potential measured across resistor A is twice that across resistor B. If the resistance of resistor B is R, what is the resistance of A?

a. R/2

b. 2R

c. R/4

d. 4R

10. When a battery goes "bad", which of the following is most likely to have happened?

a. The voltage was used up.

b. The battery's internal resistance increased.

c. The battery's internal resistance decreased.

d. The voltage was used up as well as the internal resistance decreased.

11. When an external resistor of resistance R1 = 16 Ohms is connected to the terminals of a battery, a current of 6 A flows through the resistor. When an external resistor of resistance R2 62.4 Ohms is connected instead, the current is 2 A.

a. Calculate the emf of the battery.

b. Calculate the internal resistance of the battery.

12. Find the current in the circuit shown below.

13. Find the current everywhere in the following circuit.

14. Distinguish between a short circuit and an open circuit.

15. Fill in the blanks:

a. The equivalent resistance of two resistors joined in parallel is always ________________ than the magnitude of the smaller resistor.

b. The equivalent resistance of two resistors joined in series is always ______________ than the magnitude of either resistor.

c. Resistors connected in series all have the same _______________________.

d. Resistors connected in parallel all have the same _______________________.

1. The magnetic force on a wire carrying a current is

a. perpendicular to the direction of the current flow and the direction of the magnetic field.

b. perpendicular to the current flow and parallel to the magnetic field.

c. parallel to the current flow and perpendicular to the magnetic field.

d. independent of the relative directions of the field and current.

2. The force on a charged particle moving in a magnetic field is proportional to

a. the speed of the particle.

b. the magnitude of the field.

c. the magnitude of the charge.

d. all of the above.

3. When a charged particle enters a magnetic field traveling so that its velocity vector is perpendicular to B, its path will be

a. a parabola.

b. an ellipse.

c. a circle.

d. a logarithmic spiral.

4. What is the torque on a magnet with a magnetic moment of 5.6 A.m²‚ when it is placed at an angle of 35^ø relative to a magnetic field where B = 0.15 T?

a. 0.48 N.m

b. 0.72 N.m

c. 0.97 N.m

d. 4.6 N.m

5. A coil is to be wound with a radius of 10 cm. It is to carry a current of 1.80 A and must produce a magnetic field of 1.0 mT at its center. How many turns are required?

a. 32

b. 88

c. 190

d. 370

6. A square loop has sides 12 cm long and is wound with 50 turns of wire carrying 250 mA of current. It is placed in a uniform magnetic field so the magnetic moment vector makes an angle of 70^ø with respect to B. If B = 0.65 T, what torque does the loop experience?

a. 0.11 N.m

b. 0.63 N.m

c. 0.87 N.m

d. 1.4 N.m

7. A solenoid that is 1.6 m long is wound with 3000 turns of wire that carries 1.8 A of current. What is B inside the solenoid?

a. 0.0042 T

b. 0.011 T

c. 0.073 T

d. 0.13 T

8. We desire to measure the current through and the voltage across a resistor connected in a circuit. How should an ammeter and a voltmeter be connected to the resistor?

a. Both are connected in parallel with the resistor.

b. Both are connected in series with the resistor.

c. The ammeter is connected in series and the voltmeter is connected in parallel with the resistor.

d. The ammeter is connected in parallel and the voltmeter is connected in series with the resistor.

9. If the magnetic field is directed toward the north and a positively charged particle is moving toward the west, what is the direction of the magnetic force on the particle?

a. Up

b. Down

c. East

d. South

10. An electron is traveling horizontally east in Earth's magnetic field. What is the direction of the magnetic force on the particle?

a. Up

b. Down

c. West

d. Zero

11. An electron moving with a velocity v to the right enters a region of uniform magnetic field that point out of the page. After the electron enters this region, it will be

a. deflected downward.

b. deflected upward.

c. undeflected.

d. deflected into the plane of the page.

12. In the sketch, the two long straight wires are separated by a distance of d = 36 cm. The currents are I1 = 8 A to the right in the upper wire and I2 = 5 A to the left in the lower wire. What is the magnitude and direction of the magnetic field at point T, that is a distance of d/2 = 18 cm below the lower wire?

13. What is the magnitude of the magnetic field a distance of 2 m from a long straight wire that carries a current of 20 A?

14. Describe what the right-hand rule is and how to use it.

15. Draw and label the magnetic field lines associated with

a. a dipole.

b. a long, straight, current-carrying wire.

1. Lenz's law states that

a. the induced emf is proportional to the magnetic flux.

b. the induced field opposes the change that produced it.

c. the induced emf will produce an induced current.

d. all of the above statements are true.

2. When a coil of wire rotates in a magnetic field, the induced emf will be maximum at the moment

a. the plane of the loop is parallel to the field.

b. the plane of the loop is perpendicular to the field.

c. the flux through the loop is maximum.

d. the plane of the loop is at 45^ø relative to the field.

3. An electric generator converts

a. chemical energy into electrical energy.

b. heat energy into chemical energy.

c. electrical energy into mechanical work.

d. mechanical energy into electrical energy.

4. An electromagnetic wave consists of

a. high speed electrons.

b. coupled electric and magnetic fields.

c. mechanical disturbances of the ether.

d. high speed protons.

5. A 3.0 A current produces a flux of 0.0058 T.m‚ in a coil with 1200 turns of wire. What is its inductance?

a. 0.69 H

b. 1.7 H

c. 2.3 H

d. 3.6 H

6. Calculate the current necessary to store 10 J of energy in a 3.5 H inductor.

a. 0.88 A

b. 2.4 A

c. 3.1 A

d. 6.3 A

7. The moon is 3.8 x 10⁸ m from the Earth. Calculate the time required for a radar signal to reach the moon and reflect back to the Earth.

a. 0.56 s

b. 1.2 s

c. 2.6 s

d. 4.1 s

8. A square loop that has sides 15 cm long is placed in a uniform magnetic field so that the plane of the loop makes an angle of 55^ø relative to B. If B = 0.72 T, what is the magnetic flux through the loop?

9. Calculate the inductance of a solenoid containing 500 turns if the length of the solenoid is 15 cm and its diameter is 25 mm.

10. How much energy is stored in a 75 mH inductor that carries a current of 2.4 A?