General Studies

A pulsar, black hole, and quasar are all astronomical objects found in space. A brittle star is a marine animal related to starfish, not an object in space.

When moving from a bright environment to a dark room, the pupil needs to let in more light to help the eye adjust. The iris expands (or the pupil dilates) to increase the amount of light entering the eye.

Soft iron is a ferromagnetic material that is easily magnetized and demagnetized, making it ideal for creating strong temporary electromagnets. Steel retains magnetism, making it better for permanent magnets.

According to Newton's second law, force is the rate of change of momentum (F = dp/dt). When the same force acts on two different bodies for the same time interval, the impulse applied to both is identical, resulting in both bodies acquiring the same momentum.

A voltmeter is designed to measure potential difference across a component and must be connected in parallel. To ensure it does not draw significant current from the circuit, it is built with a very high internal resistance.

Glycerol acts as an antifreeze agent when added to water. It lowers the freezing point of the mixture, preventing the radiator water from freezing in cold climates.

Standing up raises the center of gravity of the passenger-boat system. A higher center of gravity makes the system less stable and more prone to tipping or rocking.

In a capillary tube, water rises to a height where the weight of the water column balances the surface tension force. If the tube is shorter than this equilibrium height, the water will simply rise to the top of the tube without overflowing.

Babies have a higher surface area to volume ratio compared to adults. This causes them to lose heat much faster to the environment, requiring them to be kept warmer.

A fuse wire is designed to have a low melting point. When excessive current flows, the wire heats up and melts, breaking the circuit to protect appliances from damage.

Silver halides are light-sensitive compounds. When exposed to light, they undergo a chemical reduction process, which is the fundamental principle behind traditional film photography.

An aneroid barometer measures atmospheric pressure using a flexible metal box (aneroid cell) that expands or contracts with pressure changes, rather than using a liquid like mercury.

Soft X-rays have low penetrating power. They can distinguish between materials of different densities or compositions, such as identifying the metallic content of genuine coins versus counterfeit ones.

A good fuel should have a high calorific value to provide maximum energy per unit mass. A low calorific value would make it inefficient.

The Sea of Tranquility and the Ocean of Storms are large, dark basaltic plains on the Moon, formed by ancient volcanic eruptions.

As sunlight enters the atmosphere, it bends due to the change in density of the air layers. This refraction allows us to see the sun even after it has physically dipped below the horizon.

Tetraethyl lead was historically added to gasoline as an anti-knock agent to prevent premature detonation (knocking) in internal combustion engines.

The human body maintains internal pressure through blood and other fluids. This internal pressure is roughly equal to or slightly higher than the external atmospheric pressure, which prevents us from being crushed.

At high altitudes, atmospheric pressure is lower. The internal blood pressure in the capillaries remains higher than the external pressure, which can cause delicate vessels in the nose to rupture.

Adhesion is the force of attraction between different types of molecules. The dental plate clings to the roof of the mouth due to the adhesive force between the saliva and the plate/mouth surface.

Sputnik 1 was the first artificial Earth satellite, launched by the Soviet Union on October 4, 1957.

High humidity levels, especially when air is saturated, prevent sweat from evaporating efficiently. This lack of cooling leads to a feeling of discomfort and uneasiness.

Total internal reflection occurs only when light travels from a medium with a higher refractive index to one with a lower refractive index. Glass has a higher refractive index than air.