Questions

Why does a cannon recoil after firing ?

An image formed by a concave mirror on a screen is called __________?

The value of acceleration due to gravity (g) at a distance of 2R from the surface of earth, where R is the radius of earth is ______.

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.
DE, BG, YJ, ?

In the following question, out of the four alternatives, select the alternative which is the best substitute of the phrase.
One who values practicality

In the following question, a sentence / a part of sentence is underlined. Below are given alternatives to the underlined part which may improve the sentence. Choose the correct alternative. In case no improvement is required, choose "No Improvement" option.

Old habit die hardly.

Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.

In the world today we make health an end in itself. We have forgotten that health really means to enable a person to do his work and do it well. A lot of modern medicine, and this includes many patients as well as many physicians, pay very little attention to health but very much attention to those who imagine they are ill. Our great concern with health is shown by the medical columns in newspapers, the health articles in popular magazines and the popularity of television programmes and all those books on medicine. We talk about health all the time. Yet for the most part the only result is more people with imaginary illness. A healthy man should not be wasting time talking about health : he should be using health for work.

Modern medicine is primarily concerned with

Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.

Crude mineral oil comes out of the earth as a thick brown or black liquid with a strong smell. It is a complex mixture of many different substances, each with its own individual qualities. Most of them are combinations of hydrogen and carbon in varying proportions. Such hydrocarbons are also found in other forms such as bitumen, asphalt and natural gas. Mineral oil originates from the carcasses of tiny animals and from plants that live in the sea. Over million of years, these dead creatures form large deposits under sea­bed and ocean currents cover them with a blanket of sand and silt. As this material hardens, it becomes sedimentary rock and effectively shuts out the oxygen, thus preventing the complete decomposition of the marine deposits underneath. The layers of sedimentary rocks become thicker, and heavier. Their pressure produces heat, which transforms the tiny carcasses into crude oil in a process that is still going on today.

Sedimentary rocks leads to the formation of oil deposits because