Name: _____________________________ Class: __45T
Multiple Choice (2 points each)
Identify the choice that best completes the statement or answers the question.
____ 1. How should the plane of the coil of a tangent galavanometer be positioned to measure the earth’s magnetic field?
a.
Vertical in the magentic East-West direction b.
Flat on the table c.
d.
Vertical in the magnetic North-South direction
Vertical, direction does not matter
____ 2. A ray of light is incident on a flat mirror with an incident angle of 30º. What is the reflected angle?
a.
30º b.
60º c.
d.
90º
45º
____ 3. When an object is reflected in a plane mirror, how does the image distance related to the object distance?
a.
Image distance = object distance c.
Image distance < object distance b.
Image distance > object distance d.
They are not related.
____ 4. Spherical aberration occurs when light rays passing through the outer edge of the lens are focused
____________ the lens than rays passing through the center of the lens.
a.
farther from c.
at the same distance from b.
closer to d.
at the surface of
____ 5. Which atomic gas shows more emission lines?
a.
hydrogen b.
helium c.
both the same
Short Answer - SHOW YOUR WORK!
6. Practical component (15 pts). Set up a circuit with the given resistors in parallel . Turn the power supply knob until the total voltage in the circuit is 3 V. Have the instructor check your circuit and initial this page. ___________
List the resistance and current for each resistor:
R1=___________ ohms R2 =___________ ohms
I1 =___________ amps I2 =___________ amps
What is the total current in the circuit? Itotal = ___________A
.
4

Name: ________________________ ID: A
7. Practical component (15 pts). Find the focal length of the lens on the optical bench. Show any work, including calculations, for full credit.
Record the focal length of the given lens f =_____________cm
.
8. (5 pts) Following is a schematic showing the 6 terminals on a double-pole, double-throw switch as it is used in a circuit.
If the switch is in the “UP” position, show the path that the current takes through the circuit
(including through the switch).
2

Name: ________________________
9. (5 pts) Describe how a galvanometer works.
.
10. (10 pts) Sketch the path of the incident light ray as it travels from air (n=1) to glass (n=1.5).
Calculate and label the angle of refraction inside the glass slab.
ID: A
.
11. (5 pts) In the previous figure showing the ray through the glass slab, what is the angle of refraction as the light ray exits the glass slab?
3

Name: ________________________ ID: A
12. (5 pts) What is the focal length of the second lens (f
2
)? Given the figure below with a virtual object.
.
13. (5 pts) How are stars classified as different spectral types? What is one physical characteristic of a star that is linked to its spectral type?
.
4

Name: ________________________
14. (5 pts) What is a diffraction grating and what does it do?
ID: A
.
15. (15 pts) Given in this table is the data for the number of turns of wire, current, and the angle of deflection for a tangent galvanometer. The radius of the coil of wire is R = 0.1 m. The equation and permeability are given in the equation section below. Graph the data appropriately on the graph paper and calculate the Earth’s magnetic field from the graph. Show work!
N
5
5
10
15
15
I (Amps) Angle (deg)
0.33
25
0.9
0.3
0.3
49
36
48
0.5
60
.
5

Name: ________________________
Other
16. Equations:
R = ρ
L
A
R eq , parallel
=
1
1
R
1
+ 1
R
2
+ 1
R
3
+ ...
R eq , series
= R
1
+ R
2
+ R
3
+ ...
n
1
sin θ
1
= n
2
sin θ
2
ID: A
6

MULTIPLE CHOICE
1. ANS: C
2. ANS: A
3. ANS: A
4. ANS: B
5. ANS: B
SHORT ANSWER
6. ANS:
R1 = 50, R2 = 20
I1 = 0.06
I2 = 0.15
I total = 0.21
PTS: 1
7. ANS:
1
PTS: 1
8. ANS:
1
PTS: 1
9. ANS:
1
PTS: 1
10. ANS:
25 degrees
PTS: 1
11. ANS:
1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
1
ID: A

12. ANS: p= - 30 q=10 f = 15
1/p = - 0.033
1/q=0.1
PTS: 1
13. ANS:
1
PTS: 1
14. ANS: large number of closely spaced parallel slits that separate light into component wavelengths.
PTS: 1
15. ANS:
1
PTS: 1
OTHER
16. ANS:
.
PTS: 1
ID: A
2