General Science & Ability | Constituents and Structure Solved MCQs (Set-III)

Constituents and Structure General Science MCQs for FPSC Exams

101) Which type of star is maintained by the pressure of an electron gas?
(a) Main Sequence Star
(b) White Dwarf
(c) Neutron Star
(d) Black Hole
Answer: (b)
White dwarfs are stars supported by pressure of degenerate electron gas. i.e. in their interiors thermal energy kT is much smaller then Fermi energy Ep. We shall derive the equations of structure of white dwarfs, sometimes called degenerate dwarfs, in the limiting case when their thermal pressure may be neglected, but the degenerate electron gas may be either non-relativistic. somewhat relativistic. or ultra-relativistic.

102) Which of the following first hypothesized that the Earth orbited the sun?
(a) Alexander the Great
(b) Copernicus
(c) Socrates
(d) Tycho Brahe
Answer: (b)
Nicolaus Copernicus was a Renaissance mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe.

103) The LAST manned moon flight was made in what year?
(a) 1971 (b) 1972
(c) 1973 (d) 1974
Answer: (b)
The last manned landing Apollo 17 on the Moon to date, which took place on December 11, 1972, was made by Commander Eugene Cernan and lunar module pilot Harrison Schmitt who was also the first scientist on the Moon.

104) A planet is said to be at aphelion when it is:
(a) closest to the sun
(b) farthest from the sun
(c) at it’s highest point above the ecliptic
(d) at it’s lowest point below the ecliptic
Answer: (b)

105) The word Albedo refers to which of the following?
(a) The wobbling motion of a planet
(b) The amount of light a planet reflects
(c) The phase changes of a planet
(d) The brightness of a star
Answer: (b)
Albedo is a measure of the reflectivity of a surface. The albedo effect when applied to the Earth is a measure of how much of the Sun’s energy is reflected back into space. Overall, the Earth’s albedo has a cooling effect. (The term ‘albedo’ is derived from the Latin for ‘whiteness’).

106) A pulsar is actually a:
(a) black hole
(b) white dwarf
(c) red giant
(d) neutron star
Answer: (d)

107) Astronomers use Cepheid’s principally as measures of what? Is it:
(a) size
(b) speed
(c) chemical composition
(d) distance
Answer: (d)

108) Where are most asteroids located? Is it between:
(a) Jupiter and Saturn
(b) Mars and Venus
(c) Earth and Mars
(d) Mars and Jupiter
Answer: (d)

109) The precession of the Earth refers to the:
(a) change from night to day.
(b) Earth’s motion around the sun.
(c) change in orientation of the Earth’s axis.
(d) effect of the moon on the Earth’s orbit.
Answer: (c)
Precession is the change in orientation of the Earth’s rotational axis. The precession cycle takes about 19,000 – 23,000 years. Precession is caused by two factors: a wobble of the Earth’s axis and a turning around of the elliptical orbit of the Earth itself (Thomas, 2002). Obliquity affected the tilt of the Earth’s axis, precession affects the direction of the Earth’s axis. The change in the axis location changes the dates of perihelion (closest distance from sun) and aphelion (farthest distance from sun), and this increases the seasonal contrast in one hemisphere while decreasing it in the other hemisphere ( Kaufman, 2002). currently, the Earth is closest to the sun in the northern hemisphere winter, which makes the winters there less severe (Thomas, 2002). Another consequence of precession is a shift in the celestial poles. 5000 years ago the North Star was Thuban in the constellation Draco. Currently the North Star is Polaris in the constellation Ursa Minor.

110) The Magellanic cloud is a:
(a) nebula
(b) galaxy
(c) super nova remnant
(d) star cluster
Answer: (b)

111) The comet known as Halley’s Comet has an average period of:
(a) 56 years
(b) 66 years
(c) 76 years
(d) 86 years
Answer: (c)
Halley’s Comet orbits the Sun every 76.0 years and has an orbital eccentricity of 0.97. Comet Halley was visible in 1910 and again in 1986. Its next perihelion passage will be in early 2062.

112) Which one of the following planets has no moons?
(a) Mars
(b) Neptune
(c) Venus
(d) Jupiter
Answer: (c)

113) The rocks that enter the earth’s atmosphere and blaze a trail all the way to the ground and do not burn up completely are known as:
(a) meteorites
(b) meteors
(c) asteroids
(d) none of these
Answer: (a)
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the Earth’s atmosphere and impact with the Earth’s surface

114) 95% of the Martian atmosphere is composed of what substance?
(a) Carbon dioxide
(b) Nitrogen
(c) Argon
(d) Carbon monoxide
Answer: (a)
The atmosphere of Mars is about 100 times thinner than Earth’s, and it is 95 percent carbon dioxide.

115) What is the motion called when a planet seems to be moving westward in the sky?
(a) Retrograde
(b) Parallax
(c) Opcentric
(d) Reverse parallax
Answer: (a)
Retrograde motion, in astronomy, describes the orbit of a celestial body that runs counter to the direction of the spin of that body which it orbits. Apparent retrograde motion, in astronomy, is the apparent motion of planets as observed from a particular vantage point.

116) In what year did Galileo first use an optical telescope to study the moon?
(a) 1492 (b) 1611
(c) 1212 (d) 1743
Answer: (b)

117) Geocentric means around:
(a) Jupiter (b) the Earth
(c) the Moon (d) the Sun
Answer: (b)

118) The Pythagoreans appear to have been the first to have taught that the Earth is:
(a) at the center of the Universe.
(b) spherical in shape.
(c) orbits around the sun.
(d) flat with sharp edges.
Answer: (b)

119) A device which would not work on the Moon is:
(a) thermometer
(b) siphon
(c) spectrometer
(d) spring balance
Answer: (b)
Siphons will not work in the International Space Station where there is air but no gravity, but neither will they work on the Moon where there is gravity but no air

120) Of the following colors, which is bent least in passing through aprism?
(a) orange (b) violet
(c) green (d) red
Answer: (d)

121) In a reflecting telescope where in the tube is the objective mirror placed?
(a) the top to the tube
(b) the middle of the tube
(c) the bottom of the tube
(d) the side of the tube
Answer: (c)

122) What does it mean when someone says that comets have eccentric orbits? Does it mean
(a) they have open orbits
(b) they have nearly circular orbits
(c) their orbits are unpredictable
(d) the sun is far from the foci of their orbits
Answer: (d)

123) What causes the gas tail of a comet to always point away from the sun?
(a) solar wind
(b) air pressure
(c) centrifugal force
(d) gravity
Answer: (a)

124) What are Saturn’s rings composed of?
(a) completely connected solid masses
(b) billions of tiny solid particles
(c) mixtures of gases
(d) highly reflective cosmic clouds
Answer: (b)

125) Of the following, which is the only planet which CANNOT be seen with the unaided eye?
(a) Jupiter
(b) Mars
(c) Neptune
(d) Saturn
Answer: (c)
The ice giant Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. Nearly 4.5 billion kilometers (2.8 billion miles) from the Sun, Neptune orbits the Sun once every 165 years. It is invisible to the naked eye because of its extreme distance from Earth. In 2011 Neptune completed its first orbit since its discovery in 1846.

126) Accretion is:
(a) the gradual accumulation of matter in one location usually due to gravity.
(b) the process of moon formation for planets.
(c) the process of matter accumulation due to centripetal force.
(d) the disintegration of matter.
Answer: (b)

127) A blue shift means a Doppler shift of light from a(an)
(a) receding star.
(b) blue star.
(c) approaching star.
(d) fixed star.
Answer: (c)
In the Doppler effect for visible light, the frequency is shifted toward the blue end of the spectrum when the light source (such as a star) is approaching.

128) The first and largest asteroid discovered was:
(a) Pallas.
(b) Juno.
(c) Ceres.
(d) Trojan.
Answer: (c)

129) The Crab Nebula consists of the remnants of a supernova which was observed by:
(a) Brahe in 1572.
(b) Kepler and Galileo in 1604.
(c) the Chinese in 1054 A.D.
(d) several ancient civilizations in 236 B.C.
Answer: (c)
The Crab Nebula, the result of a supernova noted by Earth-bound chroniclers in 1054 A.D., is filled with mysterious filaments that are are not only tremendously complex, but appear to have less mass than expelled in the original supernova and a higher speed than expected from a free explosion. The Crab Nebula spans about 10 light-years. In the nebula’s very center lies a pulsar: a neutron star as massive as the Sun but with only the size of a small town. The Crab Pulsar rotates about 30 times each second.

130) The atmosphere of Venus contains mostly
(a) oxygen
(b) carbon dioxide
(c) nitrogen
(d) water
Answer: (b)
The atmosphere of Venus is composed of about 96% carbon dioxide, with most … various other corrosive compounds, and the atmosphere contains little water.

131) On the celestial sphere, the annual path of the Sun is called
(a) the eclipse path.
(b) ecliptic.
(c) diurnal.
(d) solstice.
Answer: (b)
The ecliptic is an imaginary line on the sky that marks the annual path of the sun. It is the projection of Earth’s orbit onto the celestial sphere.

132) The angular distance between a planet and the Sun, as viewed from the Earth, is called
(a) angle of inclination.
(b) elongation.
(c) latitude.
(d) opposition.
Answer: (b)
Elongation is the angular distance between the sun, and another object such a moon or a planet as seen from earth. There are several special names for these angular distances. The different names of these angles depend on the status, inferior or superior, of the planet. The planets closer to the sun than the earth are called inferior planets. The planets farther away from the sun than earth are called superior planets.
Elongation is measured from earth as the angle between the sun and the planet. Sometimes the apparent relative position of a planet in relation to the sun is called the aspect, or configuration, of a planet.

133) Which of the following has the highest density?
(a) Earth
(b) Venus
(c) Mars
(d) Jupiter
Answer: (a)
Earth has the highest density of any planet in the Solar System, at 5.514 g/cm3. This is considered the standard by which other planet’s densities are measured. In addition, the combination of Earth’s size, mass and density also results in a surface gravity of 9.8 m/s². This is also used as a the standard (one g) when measuring the surface gravity of other planets.

134) Which of the following planets is NOT a terrestrial planet?
(a) Earth
(b) Jupiter
(c) Mars
(d) Mercury
Answer: (b)
The term terrestrial planet is derived from the Latin “Terra” (i.e. Earth). Terrestrial planets are therefore those that are “Earth-like”, meaning they are similar in structure and composition to planet Earth. All those planets found within the Inner Solar System – Mercury, Venus, Earth and Mars – are examples of terrestrial planets. Each are composed primarily of silicate rock and metal, which is differentiated between a dense, metallic core and a silicate mantle.

135) Why do we see lunar eclipses much more often than solar eclipses?
(a) Lunar eclipses occur more often than solar eclipses.
(b) Lunar eclipses last longer than solar eclipses.
(c) The lunar eclipse is visible to much more of the Earth than a solar eclipse.
(d) The moon is closer to the Earth than the sun.
Answer: (c)
Lunar and solar eclipses occur with about equal frequency. Lunar eclipses are more widely visible because Earth casts a much larger shadow on the Moon during a lunar eclipse than the Moon casts on Earth during a solar eclipse. As a result, we are more likely to see a lunar eclipse than a solar eclipse.

136) A star like object with a very large red shift is a
(a) Neutron star.
(b) Nova.
(c) Quasar.
(d) Supernova.
Answer: (c)
Quasars: In the 1930’s, Edwin Hubble discovered that all galaxies have a positive redshift. In other words, all galaxies were receding from the Milky Way.

137) The apparent magnitude of an object in the sky describes its
(a) Size
(b) Magnification
(c) Brightness
(d) Distance
Answer: (c)

138) The Van Allen belts are:
(a) caused by the refraction of sunlight like rainbows.
(b) charged particles trapped in the Earth’s magnetic field.
(c) caused by the reflection of polar snow.
(d) caused by precession.
Answer: (b)
The Van Allen belts are a collection of charged particles, gathered in place by Earth’s magnetic field. They can wax and wane in response to incoming energy from the sun, sometimes swelling up enough to expose satellites in low-Earth orbit to damaging radiation.

139) A coordinate system based on the ecliptic system is especially useful for the studies of
(a) Planets
(b) Stars
(c) The Milky Way
(d) Galaxies
Answer: (a)

140) The mean distance of the earth from the sun in astronomical units is:
(a) 3.7 (b) 10
(c) 1 (d) 101
Answer: (c)
In astronomy, an astronomical unit is defined as the average distance from the Sun to the Earth, or about 150 million kilometers (93 million miles). You can abbreviate astronomical unit as AU.
Since the distances in astronomy are so vast, astronomers use this measurement to bring the size of numbers down.
For example, Earth is 1 au from the Sun, and Mars is 1.523 AU. That’s much easier than saying that Mars is 227,939,000 km away from the Sun.

141) What process produces a star’s energy?
(a) hydrogen and oxygen combustion
(b) nuclear fusion
(c) neutron beta decay
(d) nuclear fission
Answer: (b)
The enormous luminous energy of the stars comes from nuclear fusion processes in their centers. Depending upon the age and mass of a star, the energy may come from proton-proton fusion, helium fusion, or the carbon cycle.

142) What is the most distant object in the sky that the human eye can see without optical instruments?
(a) The Horsehead Nebula
(b) The Andromeda Galaxy
(c) The Sagittarius Constellation
(d) The Aurora Borealis
Answer: (b)
The Andromeda Galaxy (M31) is the closest large galaxy to the Milky Way and is one of a few galaxies that can be seen unaided from the Earth. In approximately 4.5 billion years the Andromeda Galaxy and the Milky Way are expected to collide and the result will be a giant elliptical galaxy. Andromeda is accompanied by 14 dwarf galaxies, including M32, M110, and possibly M33 (The Triangulum Galaxy).

143) Which civilization developed and implemented the first solar calendar?
(a) Babylonian
(b) Greek
(c) Egyptian
(d) Aztec
Answer: (c)
A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun and is based on the seasonal year of approximately 365 1/4 days, the time it takes the Earth to revolve once around the Sun. The Egyptians appear to have been the first to develop a solar calendar, using as a fixed point the annual sunrise reappearance of the Dog Star — Sirius, or Sothis — in the eastern sky, which coincided with the annual flooding of the Nile River. They constructed a calendar of 365 days, consisting of 12 months of 30 days each, with 5 days added at the year’s end. The Egyptians’ failure to account for the extra fraction of a day, however, caused their calendar to drift gradually into error.

144) What is the HOTTEST region of the sun?
(a) The core
(b) The photosphere
(c) The chromospheres
(d) The corona
Answer: (d)
The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the solar surface (the photosphere) The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more, up to a few million K. The corona cannot be seen with the naked eye except during a total solar eclipse, or with the use of a coronagraph. The corona does not have an upper limit.
A study published in 2012 in Nature Communications by researchers at Northumbria University found a possible mechanism that causes some stars to have a corona that is almost 200 times hotter than their photosphere (the star’s surface).

145) The same side of the moon always faces the Earth because:
(a) the moon is not rotating about its axis.
(b) the moon’s motion was fixed at its creation by the laws of inertia.
(c) tidal forces keep the moon’s rotation and orbiting motion in sync with each other.
(d) the moon’s magnetic poles keep aligned with the Earth’s magnetic field.
Answer: (b)

146) The resolving power of a telescope depends on the:
(a) focal ratio
(b) diameter of the objective
(c) magnification
(d) focal length
Answer: (b)
The resolving power of a telescope depends on the diameter of the telescope’s light-gathering apparatus, or objective. In a refracting telescope, the objective lens is the first lens the light passes through. In a reflecting telescope, the objective is the telescope’s primary mirror. In a Schmidt-Cassegrain telescope, the objective is also the primary mirror. As the diameter of the telescope’s objective increases, the resolving power increases.

147) On a clear, dark, moonless night, approximately how many stars can be seen with the naked eye?
(a) 300 (b) 1,000
(c) 3,000 (d) 10,000
Answer: (c)
On any clear dark moonless night a person can see about 3000 stars of our galaxy without the aid of a telescope

148) The study of the origin and evolution of the universe is known as:
(a) Tomography
(b) cystoscopy
(c) cryology
(d) cosmology
Answer: (d)
Cosmology is the branch of astronomy involving the origin and evolution of the universe, from the Big Bang to today and on into the future. According to NASA, the definition of cosmology is “the scientific study of the large scale properties of the universe as a whole.”

149) According to Kepler’s Laws, all orbits of the planets are:
(a) ellipses
(b) parabolas
(c) hyperbolas
(d) square
Answer: (a)
Johannes Kepler, working with data painstakingly collected by Tycho Brahe without the aid of a telescope, developed three laws which described the motion of the planets across the sky.
1. The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus.
2. The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.
3. The Law of Periods: The square of the period of any planet is proportional to the cube of the semimajor axis of its orbit.
Kepler’s laws were derived for orbits around the sun, but they apply to satellite orbits as well.

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