PHYS 1010 Exam 3 Question and
answers already passed 2026/2027
What to you have after cutting a bar magnet in half?
a. Two smaller magnets, each with its own north and south poles.
b. Two separated magnetic poles, one piece would be a north pole and the other a south pole.
c. Two smaller pieces of bar, but neither piece would be magnetic. - correct answer ✔a. Two smaller
magnets, each with its own north and south poles.
Non-invasive proton beam radiosurgery for brain and spinal tumors and arteriovenous malformations
uses protons with a velocity of about 5.0x10 6 m/s. Calculate the force on a proton moving with this
velocity perpendicular to a 0.7 T magnetic field.
a. 5.6x10-13 N
b. 2.9x10-7 N
c. 3.5x106 N
d. 7.1x106 N
e. 9.0x109 N - correct answer ✔a. 5.6x10-13 N
Suppose you had an old car that needs a 6-volt dc battery, but all you have is a 12-volt battery. You
could use the 12-volt battery in the car if you also had....
a. a step-down transformer to change the 12 volts into 6 volts.
b. a step-up transformer to change the 6 volts into 12 volts.
c. an isolation or 1-to-1 transformer.
d. a fairy godmother. You can't use a transformer to change the voltage from a dc battery. - correct
answer ✔d. a fairy godmother. You can't use a transformer to change the voltage from a dc battery.
A step-up transformer is used with a 120-V input to produce a 480-V output. The primary (input) coil has
100 turns. How many turns are on the secondary (output) coil?
,a. 25
b. 50
c. 100
d. 200
e. 400 - correct answer ✔e. 400
You are using a step-down transformer with 1000 loops in the primary and 200 loops in the secondary. If
the 120-V input is supplying 2.0 A of current, what is the current being supplied on the output
(secondary) side of the transformer. (Hint: The electrical power into the transformer must be equal to
the power out of the transformer).
a. 1.0 A
b. 2.0 A
c. 10 A
d. 5 A
e. 20 A - correct answer ✔c. 10 A
A transformer is used to step down 120V to 12V to power a portable radio. What is the ratio of the
number of turns in the primary coil to that in the secondary coil?
a. 0.02
b. 0.04
c. 0.03
d. 0.05 - correct answer ✔d. 0.05
A transformer is used to step down 120 V to 12 V to power a portable radio. If the radio draws 2.0 A of
current, how much current is drawn from the 120 V line?
a. 0.2 A
b. 0.4 A
, c. 0.3 A
d. 0.5 A - correct answer ✔a. 0.2 A
A transformer is used to step down 120 V to 6 V to power a portable radio if the radio draws 2.0 A of
current, how much current is drawn from the 120 V line?
a. 0.2 A
b. 0.1 A
c. 15.0 A
d. 45 A - correct answer ✔b. 0.1 A
Verify that pp = ps in the previous problem (A transformer is used to step down 120 V to 6 V to power a
portable radio if the radio draws 2.0 A of current, how much current is drawn from the 120 V line?) -
correct answer ✔120 x 0.1A = 12 W
6v = 2A = 12 W
Based on the fact that a step-down transformer uses less current on the high voltage side, what voltage
do you think is used on the street transformed in the USA?
a. More than 110 V
b. Less than 110 V - correct answer ✔a. More than 110 V
Why does a transformer blow up?
a. Heat due to current
b. Heat due to the large kinetic energy of the charged particles
c. Both of the above
d. None of the above - correct answer ✔c. Both of the above
An electric charge moving through a magnetic field experiences a force of.....
answers already passed 2026/2027
What to you have after cutting a bar magnet in half?
a. Two smaller magnets, each with its own north and south poles.
b. Two separated magnetic poles, one piece would be a north pole and the other a south pole.
c. Two smaller pieces of bar, but neither piece would be magnetic. - correct answer ✔a. Two smaller
magnets, each with its own north and south poles.
Non-invasive proton beam radiosurgery for brain and spinal tumors and arteriovenous malformations
uses protons with a velocity of about 5.0x10 6 m/s. Calculate the force on a proton moving with this
velocity perpendicular to a 0.7 T magnetic field.
a. 5.6x10-13 N
b. 2.9x10-7 N
c. 3.5x106 N
d. 7.1x106 N
e. 9.0x109 N - correct answer ✔a. 5.6x10-13 N
Suppose you had an old car that needs a 6-volt dc battery, but all you have is a 12-volt battery. You
could use the 12-volt battery in the car if you also had....
a. a step-down transformer to change the 12 volts into 6 volts.
b. a step-up transformer to change the 6 volts into 12 volts.
c. an isolation or 1-to-1 transformer.
d. a fairy godmother. You can't use a transformer to change the voltage from a dc battery. - correct
answer ✔d. a fairy godmother. You can't use a transformer to change the voltage from a dc battery.
A step-up transformer is used with a 120-V input to produce a 480-V output. The primary (input) coil has
100 turns. How many turns are on the secondary (output) coil?
,a. 25
b. 50
c. 100
d. 200
e. 400 - correct answer ✔e. 400
You are using a step-down transformer with 1000 loops in the primary and 200 loops in the secondary. If
the 120-V input is supplying 2.0 A of current, what is the current being supplied on the output
(secondary) side of the transformer. (Hint: The electrical power into the transformer must be equal to
the power out of the transformer).
a. 1.0 A
b. 2.0 A
c. 10 A
d. 5 A
e. 20 A - correct answer ✔c. 10 A
A transformer is used to step down 120V to 12V to power a portable radio. What is the ratio of the
number of turns in the primary coil to that in the secondary coil?
a. 0.02
b. 0.04
c. 0.03
d. 0.05 - correct answer ✔d. 0.05
A transformer is used to step down 120 V to 12 V to power a portable radio. If the radio draws 2.0 A of
current, how much current is drawn from the 120 V line?
a. 0.2 A
b. 0.4 A
, c. 0.3 A
d. 0.5 A - correct answer ✔a. 0.2 A
A transformer is used to step down 120 V to 6 V to power a portable radio if the radio draws 2.0 A of
current, how much current is drawn from the 120 V line?
a. 0.2 A
b. 0.1 A
c. 15.0 A
d. 45 A - correct answer ✔b. 0.1 A
Verify that pp = ps in the previous problem (A transformer is used to step down 120 V to 6 V to power a
portable radio if the radio draws 2.0 A of current, how much current is drawn from the 120 V line?) -
correct answer ✔120 x 0.1A = 12 W
6v = 2A = 12 W
Based on the fact that a step-down transformer uses less current on the high voltage side, what voltage
do you think is used on the street transformed in the USA?
a. More than 110 V
b. Less than 110 V - correct answer ✔a. More than 110 V
Why does a transformer blow up?
a. Heat due to current
b. Heat due to the large kinetic energy of the charged particles
c. Both of the above
d. None of the above - correct answer ✔c. Both of the above
An electric charge moving through a magnetic field experiences a force of.....
