Physics PHY 2002 Exam 3 with Complete
Solutions-St Francis Collage
1. The resistivity of gold is 2.44 × 10-8 Ω · m at a temperature of 20°C. A
gold wire,
0.5 mm in
diameter and 44 cm long, carries a current of 380 ma. The number of
electrons per second
passing a given cross section of the wire, is closest to:
A) 2.4 × 1018
B) 2.4 × 1017
C) 1.2 × 1022
D) 2.8 × 1014
E) 6.3 × 1015
Answer: A
2. A device with a resistance of 200.0 kΩ is connected to a 10.0 V
battery. How much power
does the device use?
A) 0.50 mW B) 20,000 kW C) 0.050 mW D) 2000 kW
Answer: A
3. Each of the resistors in the circuit shown in Figure has a resistance of
180.0 Ω.
What is
the equivalent resistance of the circuit?
A) 450.0 Ω B) 720.0 Ω C) 540.0 Ω D) 180.0 Ω
Answer: A
4. The emf and the internal resistance of a battery are as shown. In Figure, a
current of
4.7 A is drawn from the battery when a resistor is connected across the
terminals. The power dissipated by the resistor is closest to:
A) 280 W B) 340 W C) 320 W D) 300 W E) 370 W
Answer: A
1
, 5. Right now, I am in Italy drinking a glass of wine with a
couple of friends on the beach. I know you are in pain while I am
having a great time. Well, I was in your shoes twenty years ago.
Which wine do you think I am drinking:
A) Falanghina
B) Chardoney (if they shoot me)
C) Chiraz (if they shoot me)
D) Cabernet (if they shoot me)
6.A charged particle of mass 0.0040 kg is subjected to a 4.0 T magnetic field
which acts at a right angle to its motion. If the particle moves in a circle of
radius 0.10 m at a speed of 2.0 m/s, what is the magnitude of the charge on
the particle?
A) 0.020 C B) 50 C C) 0.00040 C D) 2500 C
Answer: A
7.A wire carrying a current is shaped in the form of a circular loop of radius
4.0 mm. If the magnetic field strength at its center is 1.1 mT with no
external magnetic fields contributing to it, what is the magnitude of the
current that flows through the wire?
A) 7.0 A B) 28A C) 14A D) 17 A
Answer: A
8. An electron enters a magnetic field of 0.69 T with a velocity
perpendicular to the direction of the field. At what frequency does the
electron traverse a circular path? (The mass of an electron is 9.1 × 10-31
kg, and the charge of an electron is 1.6 × 10-19 C.)
A) 1.9 × 1010 Hz B) 5.3 × 10-7 Hz
C) 1.9 × 1014 Hz D) 5.3 × 10-11 Hz
Answer: A
9. The magnitude of a magnetic field a distance 3.0 μm from a wire is
20.0 × 10-4 T. How much current is flowing through the wire. Assume the
wire is the only contributor to the magnetic field.
A) 30 mA B) 188 mA C) 19 mA D) 377 mA
Answer: A
10. A negatively charged particle is moving to the right, directly above a
2
Solutions-St Francis Collage
1. The resistivity of gold is 2.44 × 10-8 Ω · m at a temperature of 20°C. A
gold wire,
0.5 mm in
diameter and 44 cm long, carries a current of 380 ma. The number of
electrons per second
passing a given cross section of the wire, is closest to:
A) 2.4 × 1018
B) 2.4 × 1017
C) 1.2 × 1022
D) 2.8 × 1014
E) 6.3 × 1015
Answer: A
2. A device with a resistance of 200.0 kΩ is connected to a 10.0 V
battery. How much power
does the device use?
A) 0.50 mW B) 20,000 kW C) 0.050 mW D) 2000 kW
Answer: A
3. Each of the resistors in the circuit shown in Figure has a resistance of
180.0 Ω.
What is
the equivalent resistance of the circuit?
A) 450.0 Ω B) 720.0 Ω C) 540.0 Ω D) 180.0 Ω
Answer: A
4. The emf and the internal resistance of a battery are as shown. In Figure, a
current of
4.7 A is drawn from the battery when a resistor is connected across the
terminals. The power dissipated by the resistor is closest to:
A) 280 W B) 340 W C) 320 W D) 300 W E) 370 W
Answer: A
1
, 5. Right now, I am in Italy drinking a glass of wine with a
couple of friends on the beach. I know you are in pain while I am
having a great time. Well, I was in your shoes twenty years ago.
Which wine do you think I am drinking:
A) Falanghina
B) Chardoney (if they shoot me)
C) Chiraz (if they shoot me)
D) Cabernet (if they shoot me)
6.A charged particle of mass 0.0040 kg is subjected to a 4.0 T magnetic field
which acts at a right angle to its motion. If the particle moves in a circle of
radius 0.10 m at a speed of 2.0 m/s, what is the magnitude of the charge on
the particle?
A) 0.020 C B) 50 C C) 0.00040 C D) 2500 C
Answer: A
7.A wire carrying a current is shaped in the form of a circular loop of radius
4.0 mm. If the magnetic field strength at its center is 1.1 mT with no
external magnetic fields contributing to it, what is the magnitude of the
current that flows through the wire?
A) 7.0 A B) 28A C) 14A D) 17 A
Answer: A
8. An electron enters a magnetic field of 0.69 T with a velocity
perpendicular to the direction of the field. At what frequency does the
electron traverse a circular path? (The mass of an electron is 9.1 × 10-31
kg, and the charge of an electron is 1.6 × 10-19 C.)
A) 1.9 × 1010 Hz B) 5.3 × 10-7 Hz
C) 1.9 × 1014 Hz D) 5.3 × 10-11 Hz
Answer: A
9. The magnitude of a magnetic field a distance 3.0 μm from a wire is
20.0 × 10-4 T. How much current is flowing through the wire. Assume the
wire is the only contributor to the magnetic field.
A) 30 mA B) 188 mA C) 19 mA D) 377 mA
Answer: A
10. A negatively charged particle is moving to the right, directly above a
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