GATE Questions

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A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world. Scientific theories are not ever proved in the sense of being proved to be 100% correct.

Examples of some scientific theories are ::

Evolution, gravity, atomic theory, the germ theory of disease, relativity, quantum theory, electromagnetic theory, layered Earth theory, etc...

According to World Bank Indicator India - Land use:

• Agriculture Land - 1797090 sq. Km (about 60.4%). 

• Forest Area - 677598 sq. Km. (about 22.08%). 

• Agriculture Irrigated land - 35 %.

Intermolecular forces :

The forces of attraction present in between the molecules or atoms or compounds is termed as intermolecular forces.


The molecule HCl is composed of hydrogen and chlorine atom. There is high difference in electronegativities therefore, it is polar in nature. The H end of HCl is permanently slightly positive charge. The Cl end of HCl has a permanent slight negative charge. the "H" in one molecule is attracted to the "Cl" in a neighbor. The intermolecular force is weak compared to a covalent bond. But this dipole-dipole interaction is one of the stronger intermolecular attractions.

It also has hydrogen bonding and dispersion forces. 

Dispersion forces are the weakest forces which are present in between all molecules or atoms.
Hydrogen bonds are present in molecules having at least one H-A bond where A is the strong electronegative atom (mainly F, Cl and N).

The seals found at Indus valley sites gave evidance of overseas trade, which was possible only with the knowledge of art of navigation.
Thus, both A and R are true & R correctly explains A.

Let he mixes the oils in the ratio = x : y

Then, the cost price of the oils = 60x + 65y

Given selling price = Rs. 68.20

=> Selling price = 68.20(x+y)

Given profit = 10% = SP - CP

=> 10/100 (60x + 65y) = 68.20(x+y)-(60x + 65y)

=> 6x + 6.5y = 8.20x + 3.20y

=>2.2x = 3.3y

=> x : y = 3 : 2

Speed of train relative to man = 67 - 7 = 60 km/hr.
= 60 x 5/18 = 50/3 m/sec.

Time taken to pass the man = 600 x 3/50 = 36 sec.

To complete the vertical loop, the minimum speed required at the lowest point  = 5gR.