MCQs

Explanation
Light travels at about 300,000 kilometers per second i n a vacuum with a refractive index of 1.0, but slows down to 225,000 kilometers per second in water and 200,000 kilometers per second in the glass. ND16-3-2023

Explanation
Mercury revolves around the Sun every 88 days, but its rotation takes nearly 59 days.

Explanation
Sputnik 1 was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program. ND2-03-2023

Explanation
In a parallel circuit, if one bulb blows , the other bulb will remain the same. This is because each bulb in a parallel circuit has its own independent path to the power source. The failure of one bulb does not affect the current flowing through the other bulb's path.

Explanation
In liquids, particles are quite clos e together and move with random motion throughout the container . Particles move rapidly in all directions but collide with each other more frequently than gases due to shorter distances between particles. With an increase in temperature , the particles move faster as they gain kinetic energy , resulting in increased collision rates and an increased rate of diffusion. ND2-03-2023

Explanation
In space exploration , a spectroscope is typically used to analyze the light coming from stars, planets, and other celestial objects to determine their chemical composition. This helps scientists understand the formation and evolution of stars, planets, and galaxies.

Explanation
When water cools from 4°C to 0°C , ice crystals begin to form  When water freezes , the water molecules form a lattice that increases the volume. As a result, the density decreases ** ND22-1-2023

Explanation
When light shines on a photovoltaic (PV) cell – also called a solar cell – that light may be reflected, absorbed, or pass right through the cell. The PV cell is composed of semiconductor material ; the “semi” means that it can conduct electricity better than an insulator but not as well as a good conductor like a metal. *** RY24012023

Explanation
When Galileo pointed his telescope at Jupiter, the largest planet in our solar system , he made a startling discovery. The planet had four "stars" surrounding it. *** RY24012023

Explanation
The physical weight of our body is determined by the pull of gravity on it ND20-1-2023