Mock Test-1 (Paper-1) (Question 51-100)

When an apple is inside and released from an orbiting spaceship, both the apple and the spaceship are already moving with the same orbital speed around the Earth. This is because, in orbit, the only significant force acting is gravity, providing the necessary centripetal force for circular motion.

Upon releasing the apple (supposing it is not pushed), the apple keeps moving with the same velocity as the spaceship. Thus, both remain in orbit together and experience apparent weightlessness
(microgravity).

It has been calculated in the theory of the chapter i.e.,

R₁ = (mg)/2  (1 - v²h/rga)

and R₂ = (mg)/2  (1 + v²h/rga), so R₁ < R₂

When light passes from one medium to another medium frequency does not change.

• Frequency is a fundamental characteristic of the light source (e.g., a laser or a specific lamp). Once a wave is emitted, its frequency remains constant regardless of the medium it travels through.
• For a wave to remain continuous at the boundary between two media, the number of wave cycles arriving at the interface per second must equal the number of wave cycles leaving it per second.
• Frequency is directly related to the energy of photons. Since energy is conserved as light moves between media, the frequency remains unchanged.

Night vision cameras have three important features namely amplified light, infrared sensors as well as heat radiation from objects. While, x-rays radiations from objects are nit used by these cameras.

The phenomenon responsible for the swimming pool looking shorter in depth is refraction. Refraction is the bending of light as it passes from one transparent medium into another. This occurs because the speed of light changes depending on the medium it travels through.

Consider light rays coming from the bottom of the swimming pool towards your eyes. These rays travel through water first and then enter the air.

• Light travels slower in water than it does in air.
  e When light rays move from a denser medium (like water) to a less dense medium (like air) at an angle, they bend away from the normal (an imaginary line perpendicular to the surface).
• Our brain interprets objects based on the assumption that light travels in straight lines. When the light rays from the pool bottom bend as they exit the water, our brain perceives them as having travelled in a straight line from a shallower position. This makes the
  bottom of the pool appear closer to the surface than it really is

When any object or point light source is placed between two  parallel plane mirrors, infinite images will be formed as it undergoes multiple reflection to produces the infinite images.

A dioptre, is a unit of measurement of the optical power of a lens, which is equal to the reciprocal of the focal length measured in meters (that is, 1/f metres). It is thus a unit of reciprocal length.

Hence, P = 1/f ⇒ 2 = 1/f ⇒ 0.5 meter.

as the value is positive, it is a positive lens, that is, convex.

Hence, the option (c) is true.

The chemical name for methane is tetrahydridocarbon. Other common names for methane include marsh gas methyl hydride, biogas, fire damp and many more. The chemical formula formal for methane is CH₄.

• Methane is about 80 times more powerful at warming the atmosphere than carbon dioxide over a 20-year period, according to the UN Environment Programme.
• Asoutlined in the UN Environment Programme’s Global Methane Assessment, the amount of methane in the atmosphere has more than doubled since pre-industrial times, and emissions are increasing faster now than they have since the 1980s.
• Methane also contributes to the formation of ground-level ozone, a gas that is harmful to humans, ecosystems and crops, according to the Global Methane Assessment.

Yellow cakes generally denotes various compounds of uranium like uranium oxides.

• Uranium occurs naturally in low concentrations in soil, rock and water. It is a hard, dense, malleable, ductile, silver-white, radioactive metal.
• Uranium metal has a very high density.
• When finely divided, it can react with cold water. In air it is coated by uranium oxide, tarnishing rapidly.
• It can form solids solutions and intermetallic compounds with many of the metals.

Atomic bomb is a nuclear bomb that involves nuclear fission reactions. The most common isotopes and for fissile reactions are uranium (U-235) and plutonium (P-239). So in the event of an atomic bomb explosion, the most likely element that would enter the food chain us U-235, among the options.