Question Discussion & Solution

Preparing the family tree using the following symbols,

Given:

Mahendra is the son of Naman, who is the brother of Reema’s mother.

1) Mahendra is the son of Naman.

2) Naman is the brother of Reema’s mother.

We can draw following Family Tree from the information given above:

Hence, the Mahendra is the "Cousin" of Reema.

For this question,

Statements: The money plant has thin leaves and requires more water.

This statement explains the requirements and speciality of the Money plant.

Conclusion I: Plants with thin leaves require more water..

It can not be true as the statement is all about the Money plants but except for money plants, there are more plants that have thin leaves.

Conclusion II: Money plants cannot be grown in places with water scarcity.

It is completely according to the statement as it is true.

Hence, Option (4) is correct.

Additional Information

• If there are two or more sentences that are used to frame a statement, then, the sentences must be interrelated, and mutual contradiction should be there.
• Do not look for truthful notions. The information provided in the statement is the only requirement for a student to answer the question. No assumptions must be made.
• Read the statement carefully and look for keywords that are common between the statement and the conclusions
• If there is more than one conclusion that is applicable to the statement, students must ensure that the conclusions they opt for have some relation with each other.

The cube is coloured on two adjacent faces (let us consider that the top and back surfaces are coloured)

So, the cubes on the surface having no colour will be 12 cubes on the front surface, 6 cubes on the right surface, 6 cubes on the left surface and 4 cubes at the bottom two surface.

So, cubes with no colour are:

12 + 6 + 6 + 4 = 28

Again, small cubes inside the big cube with no surface coloured is 8.

Therefore, cubes with no colour are = 28 + 8 = 36

The correct answer is Copper and Tin.
Key Points

• Bronze
  • Bronze is an alloy traditionally composed of copper and tin.
  • Bronze is of exceptional historical interest and still finds wide applications.
  • It was made before 3000 BC, though its use in artifacts did not become common until much later.
  • The proportions of copper and tin varied widely (from 67 to 95 percent copper in surviving artifacts), but, by the Middle Ages in Europe, certain proportions were known to yield specific properties.
  • An alloy described in an 11th-century Greek manuscript in the library of St. Mark’s, Venice, cites a proportion of one pound copper to two ounces of tin (8 to 1), approximately that used for bronze gunmetal in later times.
  • Some modern bronzes contain no tin at all, substituting other metals such as aluminum, manganese, and even zinc.

Additional Information

• Copper and Silver
  • The best-known copper-silver alloy is sterling, which is 92.5 percent silver and 7.5 percent copper.
  • In England sterling, silver is traditionally identified by the hallmark of a lion passant.
  • Coin silver is an alloy of 90 percent silver and 10 percent copper.
  • For jewelry and ornaments, 85–90 percent silver (and the balance copper) is frequently used.
  • Dental alloys of 60–70 percent silver, 18–25 percent tin, 2–14 percent copper, and 0.5–2 percent zinc are amalgamated with varying quantities of mercury to form the filling materials for cavities in teeth.
• Copper and zinc
  • Brass is an alloy of copper and zinc, of historical and enduring importance because of its hardness and workability.
  • The earliest brass was called calamine brass, which dates to Neolithic times.
  • It was probably made by the reduction of mixtures of zinc ores and copper ores.
  • In ancient documents, such as the Bible, the term brass is often used to denote bronze, the alloy of copper with tin.
• Copper and Lead
  • Leaded bronzes contain from 4 to 25 percent lead plus additions of copper and tin, and some copper-lead bearing alloys contain up to 40 percent lead.
  • All these bearing alloys are sufficiently soft so that lubrication failure does not result in damage to the bearing.
  • Lead-based bearing alloys are also known as lead-based babbitt metals or white metals.
  • These are usually antimonial lead with widely variable additions of tin or copper (or both) and arsenic to increase strength.
  • One such alloy is commonly used for railroad-car journal bearings, contains 86 percent lead, 9 percent antimony, and 5 percent tin.
  • Many alloys of lead and alkaline-earth metals, such as calcium and sodium, also are widely used as bearing materials.

The correct answer is A thin layer of silicon.

Key Points

• In computers, the chip is made up of a thin layer of silicon.
  • Computer chips are made of silicon, which is a semiconductor, and in order to make the most efficient use of it, chip manufacturers use sand that contains as much silicon as possible.
  • The mineral quartz is ideal for this purpose because its two main components are silicon and oxygen.
  • Silicon is used because it can be used as either an insulator (doesn't allow electricity to flow) or a semiconductor (allows a little flow of electricity).
  • This is important for making chips.
  • It is very, very cheap.
• Hence, option 2 is correct. 

Additional Information

• Silicon is used for electronic devices because it is an element with very special properties.
  • One of its most important properties is that it is a semiconductor.
  • This means that it conducts electricity under some conditions and acts as an insulator under others.
  • It is even the most common element in the Earth's crust. 
• Lady Ada Lovelace invented looping in computer programming​.
  • Lady Ada Lovelace wrote a complete plan describing the algorithm needed to calculate the Bernoulli numbers using two loops, demonstrating the bifurcation capabilities of the analytical machine, describing how to perform trigonometric operations that made use of variables.