Exam 3 – PHYS 112
1:00 – 1:50 PM
April 17, 2026
answer key
Test Instruction
• Calculator is allowed.
• One 3×5 inch index card is allowed with anything written on both sides.
• Only the Akindi (bubble) sheet will be collected and graded. Make sure you
bubble your answers on the Akindi sheet correctly.
• You can write on this test, but it will not be graded.
• Do NOT open this test until you are told so.
• No books, notes, headphones, earbuds, electronic devices, caps with bills, or
sunglasses.
• Standards for academic integrity will be enforced.
• All incidents of alleged academic misconduct will be reported.
Stay calm and do your best!
1
, Q1. What is the direction of the magnetic field at point P?
A. to the right
0
B. to the left
C. up
A D. down
E. into the page
F. out of the page
G. none of the above
(Q2-Q3). Two long straight wires carry currents as shown, I1 = 6.0 × 105 A and I2 = 1.0 × 105 A.
Q2. What is the magnitude of the magnetic field at the dotted point?
A. 4.5 T
B. 5.5 T
0
B C. 9.5 T
D. 6.0 T
E. 4.0 T
F. 11 T
G. 1.5 T
H. None of the above
Q3. What is the direction of the magnetic field at the dotted point?
A. to the right
B. to the left
C. up
D. down
O
D E. into the page
F. out of the page
G. None of the above
Q4. What is the direction of the magnetic field at position P, which is exactly in the middle of two parallel
wires carrying equal currents I in opposite directions?
A. to the right
B. to the left
C. up
D. down
0
E E. into the page
F. out of the page
G. None of the above
Q5. A bar magnet and a current loop are shown at right.
How do they interact with each other?
0
A. attract
B. repel
A C. no effect
2
1:00 – 1:50 PM
April 17, 2026
answer key
Test Instruction
• Calculator is allowed.
• One 3×5 inch index card is allowed with anything written on both sides.
• Only the Akindi (bubble) sheet will be collected and graded. Make sure you
bubble your answers on the Akindi sheet correctly.
• You can write on this test, but it will not be graded.
• Do NOT open this test until you are told so.
• No books, notes, headphones, earbuds, electronic devices, caps with bills, or
sunglasses.
• Standards for academic integrity will be enforced.
• All incidents of alleged academic misconduct will be reported.
Stay calm and do your best!
1
, Q1. What is the direction of the magnetic field at point P?
A. to the right
0
B. to the left
C. up
A D. down
E. into the page
F. out of the page
G. none of the above
(Q2-Q3). Two long straight wires carry currents as shown, I1 = 6.0 × 105 A and I2 = 1.0 × 105 A.
Q2. What is the magnitude of the magnetic field at the dotted point?
A. 4.5 T
B. 5.5 T
0
B C. 9.5 T
D. 6.0 T
E. 4.0 T
F. 11 T
G. 1.5 T
H. None of the above
Q3. What is the direction of the magnetic field at the dotted point?
A. to the right
B. to the left
C. up
D. down
O
D E. into the page
F. out of the page
G. None of the above
Q4. What is the direction of the magnetic field at position P, which is exactly in the middle of two parallel
wires carrying equal currents I in opposite directions?
A. to the right
B. to the left
C. up
D. down
0
E E. into the page
F. out of the page
G. None of the above
Q5. A bar magnet and a current loop are shown at right.
How do they interact with each other?
0
A. attract
B. repel
A C. no effect
2
