Exams

Which one of the following elements will be an isobar of calcium if the atomic number of calcium is 20 and its mass number is 40?

If (x/y)a-4 = (y/x)2a-5, then what is the relation between x and y?

A word is represented by only one set of numbers as given in any one of the alternatives. The sets of numbers given in the alternatives are represented by two classes of alphabets as shown in the given two matrices. The columns and rows of Matrix-I are numbered from 0 to 4 and that of Matrix-II are numbered from 5 to 9. A letter from these matrices can be represented first  by its row and next by its column ,for example 'H' can be represented by 32,41 etc and 'N' can be represented by 98,85 etc. similarly,you have to identify the set for the word ''IOTA''.

A can paint a house in 25 days and B can do it in 10 days. Along with C, they did the job in 6.25 days only. Then in how many days, C alone can do the job?

A passage is given with 5 questions following it. Read the passage carefully and choose the best answer to each question out of the four alternatives.

The quest to find life outside the solar system got a big boost with the discovery of seven Earth-size extra-solar planets, or exoplanets, orbiting a dwarf star about 40 light years away. Unlike earlier discoveries of exoplanets, all seven planets could possibly have liquid water — a key to life as we know it on Earth — with three planets having the greatest chance. This is by far the largest collection of Earth-like planets in the habitable 'Goldilocks' zone of a star — neither too close nor too far from a star, which raises the possibility of liquid water being present on the surface. Only Earth has liquid water in the solar system. Since the dwarf star is much cooler than the Sun, the dimming of light each time a planet passes or transits before the star could be easily recorded from Earth unlike in cases when planets transit a Sun-like bright star. Since the initial discovery of three planets was made using the Chile-based Transiting Planets and Planetesimals Small Telescope, the exoplanet system is called TRAPPIST-1.

What is essential to have the possibility of life on a planet?

A solid cylinder has radius of base 14 cm and height 15 cm. 4 identical cylinders are cut from each base as shown in the given figure. Heoght of small cylinder is 5 cm. What is the total surface area of the remaining part?

The process of soil formation is called

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

Modern civilization is completely dependent on energy, which has therefore to be abundant and also economical. About 85% of the world's energy is supplied by oil, coal and natural gas while nuclear, hydro, wind and solar power and biomass supply the rest. Coal, nuclear and hydro are used primarily to generate electricity while natural gas is widely used for heating. Biomass is used both for heating and cooking. The wind and solar power is the future's hope as they are sustainable energy sources. Oil powers almost all machines that move and that makes oil uniquely versatile. Oil powered airplanes carry 500 people across the widest oceans at nearly the speed of sound. Oil powered machines produce and transport food. Oil powered machines are ubiquitous. Clearly, we live in the age of oil but it is drawing to a close. According to data available if oil production remains constant until it's gone, there is enough to last 42 years. Oil wells will produce less as they become depleted, which will make it impossible to keep production constant. Similarly natural gas and coal will last another 61 years and 133 years respectively. Naturally, as they become scarce, they become expensive, leading to a worldwide energy crisis. If we are to survive on this planet, we have to make a transition to sustainable energy sources. The transition may be willy-nilly or planned - the choice is ours.

The dawning era of limited and expensive energy will be very difficult for everyone on earth but will be even more difficult if it is not anticipated. It is of utmost importance that the public and policymakers understand the global energy crisis and act in tandem to ensure that the species 'homo sapiens' does not become extinct.

Biomass is an energy source used in