Instructions
Each multiple choice question has one correct answer.
Choose the most correct answer.
Bring a calculator to the exam.
Useful information
1 hour = 3600 sec.
1 year = 3.16 x 10
7
sec.
c = 3x10
8
m/sec = 3x10
5
km/sec
n – nano = 10
-9
,
μ
- micro = 10
-6
,
m – mili = 10
-3
,
k – kilo = 10
3
,
M – mega = 10
6
1 AU = 1.53x10
11
m = 1.53x10
8
km,
1 ly = 9.5x10
15
m = 9.5x10
12
km,
K =
o
C + 273
P
P
2
= A
3
,
F = GmM/r
2
,
F = ma,
G = 6.67x10
-11
Nm
2
/kg
2
d = vt, E = hf = hc/
λ
,
f
λ
= c,
v
r
=
Δλ
/
λ
α
(arc sec) = 11.6/D(in cm),
α
(arc sec) = 0.02
λ
(nm)/D(in cm),
M = f
o
/f
e
Circumference = 2
π
r,
Area(circle) =
π
r
2
,
Area(sphere) = (4/3)
π
r
2
Volume(sphere) = (4/3)
π
r
3
1.
A lightyear is
a)
Unit of length.
b)
the length light travels in one year.
c)
is about 10
13
km.
d)
all of the above.
2.
Which one of the following statements on constellations is FALSE?
a)
there are 88 constellations in the sky.
b)
the brightest star in an constellation is designated
α
.
c)
the pattern of constellations is the same no matter how far the observer is from
the solar system.
d)
the location of the planets is not fixed in the constellations.
3.
A fast probe is sent to the nearest star Alpha Centuri about 4 ly away.
If the velocity
of the probe is 200,000 km/hour, how long will it take to reach the star?
a)
4 years
b) 300 years
c) 22000 years
d) 200,000 years
e) 2,000,000 years
4.
Once the probe arrives at Alpha Centuri, how long will it take its radio signal to
reach the Earth announcing its arrival?
a)
4 years
b) 300 years
c) 5400 years
d) 200,000 years
e) 2,000,000 years
5.
Which wave has the shortest wavelength?
a)
radio waves.
b)
gamma rays.
c) visible light.
d) ultraviolet rays.
6.
How do astronomers determine the surface temperature of a star?
a)
by determining the wavelength of spectra at peak intensity.
b)
by sending a probe that crashes into the star.
c)
by duplicating the star energy output in the laboratory.
d)
by dividing the star peak wavelength by the energy output.
7.
How much more light can a 20 cm diameter telescope gather compared to the human
eye which has a diameter of 4mm (0.4cm)?
a)