Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

A star in the main sequence will maintain a constant size

  1. as long as its helium supply holds out.

  2. because its tendency to contract is opposed by the pressure of the hot interior.

  3. until it is devoured by black holes.

  4. provided that gravitational collapse does not overwhelm its photosphere.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

All main sequence stars (including the Sun) are in hydrostatic equilibrium. That is, the inward force of gravity, which tends to compress the star, is balanced by the outward force due to the pressure.

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

Stars are believed to originate

  1. in clouds composed largely of hydrogen gas.

  2. when black holes eject excess matter and energy.

  3. when a supernova explode.

  4. when a cloud of helium starts to collapse and breaks into constituent protons (hydrogen atoms).
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Stars form within giant molecular clouds, which are composed primarily of hydrogen gas. Gravity causes these clouds to collapse, eventually leading to the formation of protostars.

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

A protostar is a developing star not yet hot enough to engage in the process of:

  1. nuclear fusion

  2. nuclear fission

  3. atomic transmission

  4. atomic emission
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

An object is considered a protostar for as long as material is still falling inward. For our Sun, and stars of the same mass, the protostar phase would have ended after approximately 100,000 years. After this, the protostar stops growing and the disk of material surrounding it is destroyed by radiation.


If the protostar was unsuccessful in acquiring enough mass, a brown dwarf will come into shape. These substellar objects that are unable to sustain hydrogen fusion reactions in their cores, due to their insufficient mass

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

The gaseous body that continues to form, now appears as a large red object called a:

  1. protostar

  2. red dwarf

  3. red star port

  4. red giant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A protostar is an early stage in stellar evolution where a cloud of gas and dust is collapsing under gravity. It is often associated with a glowing, dense, and relatively cool appearance before reaching the main sequence.

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

When the core of a protostar reaches 10 million degrees Kelvin, the pressure is so great that the nuclear fusion of which gas begins?

  1. hydroxide

  2. hydrogen

  3. heliogen

  4. hydrogate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A star's composition is mostly made of gases of which hydrogen and helium forms the most largest component of it. Hydrogen being the lightest element will get fused to helium

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

After the initial contraction and when the temperature rises high enough, energy is radiated from the surface in the form of:

  1. short-wavelength red light

  2. short-wavelength blue light

  3. long-wavelength red light

  4. long-wavelength orange light
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As a protostar contracts, it heats up and begins to radiate energy. Because the surface temperature is relatively low compared to mature stars, the radiation is primarily in the infrared or long-wavelength red spectrum.

Multiple choice physics in the world of stars evolution and end stages of stars life cycle of stars stars

What is the range of star masses for high-mass stars? 

  1. between 500 and about 1,000 solar masses

  2. between 200 and about 500 solar masses

  3. between 8 and about 100 solar masses

  4. between 2 and about 10 solar masses
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Range of star masses for high-mass stars varies from about $8$ to $200$ solar masses.

Answer is $C$.

Multiple choice physics electromagnetism magnetic field due to a circular current carrying conductor magnetic field produced in a circular loop field due to a current carrying coil oersted experiment

In a circular current-carrying conductor, if the current flows in the clockwise direction, the magnetic field direction is __________.

  1. Parallel to the coil towards the observer

  2. Perpendicular to the plane of the coil away from the observer

  3. Perpendicular to the plane of the coil towards the observer

  4. Parallel to the plane of the coil away from the observer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The magnetic field are concentric circle at point of a current carrying circular conductor direction of the magnetic field of every section of the circular loop can be found by using the right hand thumb rule .if you curl your right hand fingers in direction of magnetic field your thumb will point in the direction of the current flow.