ASTR 113 Session 003 Fall 2006

Instructor: Jie Zhang

Sample questions for exam 2. The correct choice is indicated by “*”.

The real exam will have 50 questions instead of 10, but in the same style.

1 Radio waves travel through space at what speed?

A) much faster than the speed of light

B) faster than the speed of light, since their wavelength is longer

C) slower than the speed of light

D) * at the speed of light, 3 × 10⁸ m/s

2 The observed change in wavelength due to the Doppler effect occurs

A. whenever the light source is moving with respect to the observer (regardless of direction).

B. * only when the light source has a radial velocity (toward or away from the observer).

C. only when the temperature of an object changes.

D. only when the light source has a proper motion (across the line of sight).

3 How does the speed of light in glass compare to the speed of light in a vacuum?

A. The speed of light is the same in both.

B. The speed of light in glass is faster.

C. Depending on the glass, the speed of light can be faster or slower.

D. * The speed of light in glass is slower.

4 Which of the following characteristics of an astronomical telescope is most important for determining the angular resolution?

A. the focal length of the eyepiece

B. the magnifying power of the telescope

C. *the diameter of the objective lens or mirror

D. the focal length of the objective lens or mirror

5 The correct sequence of planets in our solar system from the Sun outward is

A. Mercury, Venus, Earth, Mars, Saturn, Uranus, Jupiter, Neptune.

B. Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus,, Neptune.

C. Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus, Neptune.

D. *Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune

6 The asteroid belt is made up of

A. large, rocky bodies typically about the size of our Moon.

B. *rocky bodies from a few meters to tens of kilometers in diameter.

C. several planet-sized objects with dense methane atmospheres.

D. irregularly shaped bodies composed primarily of ices.

7 What was the form of the material from which the solar system formed?

A) *a nebula made mostly of hydrogen and helium gas, but enriched in heavier elements from supernova explosions

B) a nebula made mostly of heavy elements, but enriched in hydrogen and helium from the supernova explosions

C) a nebula made entirely of hydrogen and helium gas

D) debris from the explosion of a massive star

8 Which of the following types of material has the highest condensation temperature in the planetary system?

A. hydrogen

B. *rocks and dust grains

C. nitrogen gas

D. gases such as methane, ammonia, water vapor

9 Which of the following is the major power source that drives the dynamics of Earth's atmosphere?

A. outflow of the original heat of production from Earth's interior

B. tidal effects from the Moon and Sun

C. the burning of fossil fuels such as coal, oil, and natural gas on Earth's surface

D. *solar radiation

10 Continental drift on the Earth is a result of

A. *large-scale circulation of partly molten or plastic rock in Earth's interior.

B. water percolating down through geological fault zones, acting as a lubricant.

C. the momentum of impacts from giant asteroids or planetoids hitting the early Earth.

D. flexing of the Earth's surface by lunar and solar tides.