Which of the following is used for nuclear reactions during the death of stars?
a) energy
b) mass
c) fuel
d) radiation
Nuclear reactions outside the core cause the dying star to expand outward in the……….phase before it collapse.
a) red giant
b) blue giant
c) yellow giant
d) white dwarf
Explanation:A red giant is a luminous giant star of low or intermediate mass in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around 5,000 K or lower.
After
the formation of red giant, the core of the star ends up as one of the
………types.
a) two
b) three
c)
four
d)
six
Explanation:1. White dwarf, 2. Neutron star (or pulsar) and 3. Black hole
If the initial mass of the star is less than or equal to the mass of the solar mass, the red giant becomes…….
a) white dwarf
b) neutron star
c) black hole
d) none of these
Explanation:A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf. The nearest known white dwarf is Sirius B, at 8.6 light years.
What is the
estimated size of white dwarf?
a) moon
b) comet
c) earth
d) sun
The sun is about…….billion years old.
a) 4.5
b) 5
c) 10
d) 15
