GATE Questions

---

7 C in a R represents 7 Colours in a Rainbow.

The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.

Sodium chloride:

The solubility rules tell you that all halides are soluble with the exception of those formed with siver, mercury, and lead ions. Since this is not the case here, sodium chloride will be soluble.

Silver nitrate:

It is soluble because all nitrates are soluble, without exception.

Potassium sulfate:

It is soluble because all sulfates are soluble with the exception of those formed with silver, calcium, barium, mercury, lead, and strontium ions.

Copper (II) hydroxyde:

It is insoluble because all hydroxides are insoluble with the exception of those formed with alkali metal ions and barium.

W is the symbol for chemical element Tungsten or Wolfram.

It is used in making filaments of bulbs.

Any object rolls when there is no friction. So, Sliding to Rolling is correct.

A square and a rectangle each have 4 right (90 deg) angles. 

Both square and rctangle have 4 sides and 4 angles, but the only difference is square is a rectangle with all sides equal.

Jeff Bezos is the richest person in modern history. The Amazon.com Inc. founder’s net worth broke $150 billion in New York on 16th July 2018 morning, according to the Bloomberg Billionaires Index.

That’s about $55 billion more than Microsoft Corp. co-founder Bill Gates, the world’s second-richest person.

The P wave in the ECG represents atrial depolarization, which results in atrial contraction, or atrial systole.

The P wave is a summation wave generated by the depolarization front as it transits the atria.