General Science Physics Questions
11. Which of the following is represented by the newly discovered high-temperature superconductors?
[A] Metal alloys
[B] Pure rare-earth metals
[C] Ceramic oxides
[D] Inorganic polymers
[C] Ceramic oxides
Notes:
The first high-Tc superconductor was discovered in 1986 by IBM researchers Georg Bednorz and K. Alex Muller, who were awarded the 1987 Nobel Prize in Physics “for their important break-through in the discovery of superconductivity in ceramic materials”.
12. Due to which of the following reasons the Superconductors are so called?
- [A] Efficiently conduct heat from one hot body to another
[B] Offer no resistance to conduction of heat at high temperatures - [C] Offer no resistance to conduction of electricity at low temperatures
- [D] Produce high temperatures while conducting electricity
[C] Offer no resistance to conduction of electricity at low temperatures
Notes:
It takes a significant amount of energy to scatter an electron from the condensate – more than the thermal energy available to an electron below the critical temperature – so the superconducting electrons can flow without being scattered, that is, without any resistance.
13. When an air bubble at the bottom of a lake rises to the top, which of the following will happen to it?
[A] Increase in size
[B] Decrease in size
[C] Maintain its size
[D] Flatten into a disk-like shape
[A] Increase in size
Notes:
Pressure starts decreasing as we go upwards. That is the reason that air bubble in water grow in size when it rises from bottom to top. As the pressure exerted by water is directly proportional to the depth of water, as the depth of water increases in a water body, the pressure increases linearly.
14. According to the Kepler’s law of planetary motion, square of the time period is proportional to__?
[A] Semi-major axis
[B] Square of the semi-major axis
[C] Cube of the semi-major axis
[D] Fourth power of the semi-major axis
[C] Cube of the semi-major axis
Notes:
Kepler’s third law of planetary motion states that the square of the time period is proportional to the cube of the semi-major axis. The Ist law states that all planets revolve around the sun in the eliptical orbit while the second law states that all planets sweep equal area, in equal interval of time.
15. A system exhibiting Simple Harmonic Motion (SHM) must possess__:
[A] Elasticity as well as inertia
[B] Elasticity, inertia and an external force
[C] Elasticity only
[D] Inertia only
[A] Elasticity as well as inertia
Notes:
Basic conditions to execute simple harmonic motion are: (i) There must be an elastic restoring force acting on the system, (ii) the system must have inertia, and (iii) the acceleration of the system should be directly proportional to its displacement and is always directed to mean position.
16. Absolute Zero is defined as ________.
[A] The temperature at which all molecular motion ceases
[B] At which water boils at 298K
[C] At which liquid Helium boils
[D] At which the volume becomes zero
[A] The temperature at which all molecular motion ceases
Notes:
Absolute zero is the temperature at which all motion in matter stops and is thought to be unreachable. It is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy induced particle motion.
17. Soap bubbles look colourful in white light due to__:
[A] Diffraction
[B] Scattering
[C] Reflection
[D] Interference
[D] Interference
Notes:
A bubble’s colors are caused by a phenomenon known as Thin-film Interference. When light bounces off of a soap film, there are reflections from both the front and back of the film that reach the eye. Interaction between these reflections cause the colors that we see.
18. If cream is removed from milk, its density__:
[A] Increases
[B] Decreases
[C] Remains the same
[D] May increase or decrease
[A] Increases
Notes:
The density of pure fresh milk being on the average 1.032, while the density of fat globules is about 0.86. It follows that the removal of cream will increase the density, while the addition of water will decrease it.
19. Outside of cooking utensils are generally left black from below because__:
[A] It is difficult to clean daily.
[B] Black surface is a good conductor of heat.
[C] Black surface is a poor conductor of heat.
[D] Black surface is a good absorber of heat.
[D] Black surface is a good absorber of heat.
Notes:
The outside surface of a utensil used for heating is coated black so that it may absorb more heat and make heating quicker. This is because black surface is both a good absorber and emitter of heat.
20. Purity of a metal can be determined with the help of__:
[A] Pascal’s law
[B] Boyle’s law
[C] Archimedes principle
[D] Conservation of mass principle
[C] Archimedes principle
Notes:
Purity of a metal can be determined with the help of Archimedes Principle which makes use of the densities and buoyancy of metals. Finding the density of a metal sample can help to determine its purity. It is most commonly used in the checking the purity of gold.