Question Discussion & Solution

The correct answer is Canada.

Key Points

• The federal government system of India has been taken from the Canadian Constitution.

Additional Information

• Only the Parliament has the power to make laws on the subjects of the Union List.
• Article 245 to 255 of the Constitution discusses the Centre-State legislative relations in Part-XI.
• In the Constitution of India, three types of lists are present in the Seventh Schedule as the legislative powers between the Center and the States.
• The 'Union List' mentions important subjects, which include defence, communication, foreign policy, etc., and where only the laws of the Center are effective.

The correct answer is Magnesium Sulfate.

• Magnesium Sulfate is the industrial name of Epsom.
• Magnesium sulfate is a magnesium salt having sulfate as the counterion.
• It has a role as an anticonvulsant, a cardiovascular drug, a calcium channel blocker, an anaesthetic, a tocolytic agent, an anti-arrhythmia drug, an analgesic, and a fertilizer. It is a magnesium salt and a metal sulfate.

Key Points

• Magnesium Sulfate Formula Structure:  

Additional Information

The correct answer is Nichrome.

Key Points

• Nichrome 
  • It is a metal alloy made up of around 20 percent of chromium and 80 percent nickel.
  • The key to the workings of an electrical heating element is the role of the nichrome in it.
  • Nichrome has fast emerged as the leading alloy to be used in terms of electrical heating elements.
  • For an electric iron heater element should have higher resistance, high melting point, and high specific heat.
  • An element should have high resistance so that it can hold its configuration in a high voltage current. It should have a high melting point such that it can sustain high temperatures.
  • Nichrome is used as a heating element in electric iron which is an alloy consisting 80% of Nickel and 20% of Chromium melting point of this element is 1400 degrees Celsius with high resistance which makes this element best for use as a heating element. Hence, Option 1 is correct.
  • The reason which makes the Nichrome best for heating elements is when it is heated in the air it develops an outer layer of chromium oxide which makes it stable in air and this chromium layer helps the element from oxidizing further during heating. 

Additional Information

• Copper
  • It is a chemical element with the symbol Cu and atomic number 29.
  • It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
  • A freshly exposed surface of pure copper has a pinkish-orange color.
• Silver
  • It is a chemical element with the symbol Ag and atomic number 47.
  • A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal.
• Lead
  • It is a chemical element with the symbol Pb and atomic number 82.
  • It is a heavy metal that is denser than most common materials.
  • Lead is soft and malleable, and also has a relatively low melting point.
  • When freshly cut, lead is silvery with a hint of blue it tarnishes to a dull gray color when exposed to air.

The correct answer is Natural Gas.

Key Points

•  Fossil Fuel: Fossil Fuels are the fuels generated from the residues of living organisms (which remained buried under the earth for millions of years).
  • Examples: Coal, Petroleum, and Natural gas.
  • They are also known as Non-Renewable Natural Resources.​

 Additional Information

• Natural Gas: It is considered the best fuel because of the inflammable nature of its constituents(83% methane and 16%ethane).
  • It is used in the production of artificial chemical fertilizers. 
• Coke: It is obtained by the strong heating of coal in the absence of air as a residual substance. 
  • It contains 80-85% carbon.
  • Coke is used in the extension of metals as a reducing agent.
• Producer Gas: It is a mixture of nitrogen and carbon monoxide(in 2:1 ratio).
  • It is used in the manufacture of glass and for metallurgy. 

The correct answer is four.

Key Points

• Crocodiles have four-chamber hearts. All reptiles have incomplete four-chamber hearts except Crocodiles.

Additional Information

• Endotherm or Homeotherm have well developed four-chamber heart. Examples:- Birds and mammals. 
  • They can maintain constant body temperature.
• Poikilotherm or Ectotherm do not have a well-developed heart, so they can not maintain constant body temperature. Examples:- Amphibians and reptiles.
• Fishes have a two-chamber heart.
• Amphibians have three-chamber heart.
• The cockroach has thirteen chamber hearts.