Understand metals and non-metals well

These basic science questions can help candidates in preparing for recruitment tests

Hyderabad: These basic science questions can help candidates in preparing for recruitment tests. These practice questions focusing on general science will aid aspirants to prepare better for the State government recruitment examinations.
1. Which of the following types of coal has maximum carbon content?

a) Peat b) Lignite

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c) Anthracite d) Bituminious

Ans: c

Explanation: Often referred to as ‘hard coal’, Anthracite is a hard, compact variety of coal with submetallic lustre. It has highest carbon content, fewest impurities, and highest energy density among all types of coal. No wonder that it is the highest ranking of coals.
2. Highest percentage of nitrogen is found in which among the following fertilizers among the given options?
a) Calcium ammonium nitrate b) Ammonium nitrate
c) Calcium nitrate d) Urea
Ans: d

Explanation: Urea, white crystalline solid containing 46 per cent nitrogen, is used by the agricultural industry as an animal feed additive and fertilizer. Urea has the highest nitrogen content of all solid fertilizers at 46% N.
3. Calcium Magnesium Silicate is commonly called as ________?
a) Asbestos b) Borax

c) Baking Soda d) Washing Soda

Ans: a

Explanation: Commonly known as asbestos, CaMgO4Si is the chemical formula of calcium magnesium silicate. Asbestos is a fibrous silicate mineral and it is formed by miniature crystal fibres, which are loosely attached releasing dust of silicate crystal upon small touch.

4. The alloy steel containing chromium to resist rusting is known as stainless steel. What is the role played by chromium in stainless steel?

1. Chromium does not rust, so it works as protecting cover

2. Chromium reacts with iron to make a compound that is not affected by Oxygen

Select the correct option from the codes given below:

a) Only 1 b) Only 2 c) Both 1 & 2 d) Neither 1 nor 2

Ans: d

Explanation: Chromium basically works like a sacrificial metal. It rusts first but the rusting chromium doesn’t crumble apart. Rather, it would form an invisible thin layer that protects the iron underneath. On the other hand, the nickel in stainless steel helps hold this protective layer of chromium rust in place. The chromium and nickel are present throughout stainless steel, not just on the surface. Because of this, the microscopic layer will form itself anew, even when the steel is cut or scratched.
5. Hypotonic solution is a solution:
a) Whose osmotic pressure is less than that of another
b) Which can dissolve maximum amount of solute at given temperature
c) Of solid in gas
d) Of solid in solid
Ans: a

Explanation: Hypotonic solution is a solution whose osmotic pressure is less than that of another.
6. Consider the following differences between hard and soft water:
1. While hard water has high calcium and magnesium content, soft water has high sodium content
2. Hard water does not easily lather with soap, whereas soft water easily lathers with soap
Which of the above statements is/are correct?
a) 1 Only b) 2 Only c) Both 1 & 2 d) Neither 1 nor 2
Ans: c

Explanation: Both are correct statements. Hard water is generally found in areas where groundwater is in contact with limestone, chalk and dolomite and gets higher amount of calcium and magnesium dissolved in it. Soft water is found in areas where groundwater usually travels through peat, igneous rock or sandstone sources, and does not contain as much calcium and magnesium. In fact, it contains higher amount of sodium ions.
For more questions, visit the TS BC Study Circles Telegram group https://t.me/ Ukk7l_n7wJxmMjll.
To be continued…

By K Aloke Kumar
Director,

Telangana State BC Study Circles