Science and Technology

An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth

The surface of a lake is frozen in severe winter, but the water at its bottom is still liquid. What is the reason?

What is the principle by which a cooling system(Radiator) in a motor car works:

India-based Neutrino Observatory is included by the Planning Commission as a mega science project under the 11th five-Year Plan. In this context, consider the following statements:
1. Neutrinos are chargeless elementary particles that travel close to the speed of light.
2. Neutrinos are created in nuclear reactions of beta decay.
3. Neutrinos have a negligible, but nonzero mass.
4. Trillions of Neutrinos pass through human body every second.
Which of the statements given above are correct ?

In the year 2008, which one of the following conducted a complex scientific experiment in which sub-atomic particles were accelerated to nearly the speed of light ?

Which one of the following types of waves are used in a night vision apparatus ?

In a dry cell (battery), which of the following are used as electrolytes ?

Consider the following statements:
1. A widely used musical scale called diatonic scale has seven frequencies.
2. The frequency of the note Sā is 256 Hz and that of Nī is 512 Hz.

Which one of the following laser types is used in a laser printer?

Assertion (A): Radio waves bend in a magnetic field.
Reason (R): Radio waves are electromagnetic in nature.