Question Discussion & Solution

int add (int a, int b=12) // formal argument
{
return a + b;
}
main()
{ 
int c;
c = add (10, 20);
printf("c = %d", c);
}

In this Program Add function is following the call by value mechanism so that value cannot be called outside the function So the answer will be a+b = 10+ 20 = 30 

Therefore Option B is correct

Explanation:

• Bronze is an alloy of copper and tin as the two main constituent elements.
• Bronze is a copper-based alloy that typically consists of approximately 88% copper and 12% tin.
• Some other elements added in minute quantities can be aluminium, nickel or zinc.
• It is one of the first alloys used by mankind and an entire era known as the 'Bronze Age' is known because of the extensive use of the alloy in many human artefacts.

Additional Information

Steel: 

• Stainless steel is an alloy of iron and chromium.
• Steel is an alloy of iron and carbon.
• Stainless steels are steels containing at least 10.5% chromium, less than 1.2% carbon, and other alloying elements.

Solder:

• Soldering is a joining process used to join different types of metals together having different properties. 
• Solder is a metal alloy, usually made up of tin and lead which is melted using a hot iron (soldering iron).
• The iron is heated to temperatures above 600˚F which then cools to create a strong bond.
• Flux material used in soldering is ZnCl2 (Zinc Chloride) and NH4Cl (Ammonium Chloride).

Brass:

• Brass is a metal alloy that is made up of copper and zinc.
• The proportions of zinc and copper can vary to create different types of brasses with different properties.
• It has higher malleability than bronze or zinc and has a relatively low melting point (900 to 940 °C).

Mistake Points

• Copper was the first metal used by men.
• Copper was first used by man over 10,000 years ago.  
• Probably copper can be found as a naturally occurring native metal that is sometimes found in large lumps on the ground.
• People learned to make this into copper tools and other things, although, for a metal, it is quite soft.
• When it was melted over the fire, people learned how to make an alloy called bronze, which is much harder and stronger than copper.

Concept:

Vitamins:

• Vitamins are organic compounds that are present in minute amounts in natural foodstuffs.
• Most vitamins come from food because the body either does not produce them or produces very little.
• Vitamins are of two types.
  • Fat-soluble vitamins- Vitamins A, D, E, K.
  • Water-soluble vitamins- Vitamin C and all the B vitamins. 

• There are 13 vitamins - A, C, D, E, K, and B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate), each of them have a different job.
• Vitamin A, D, E, K are Fat-Soluble vitamins and are stored in fat cells while vitamins B and C are water-soluble vitamins that are not stored in your body.
• The liver acts as a storage site for vitamin A, D, E, K, and B12 for the times when they may be lacking in the diet.
• Vitamin D acts as a hormone, produced by the kidneys it helps to control the concentration of calcium in the blood and is vital for the development of strong bones.
• Water-soluble vitamins like Thiamine, folate, biotin, riboflavin are synthesized by gut bacteria.

Explanation:

• Vitamin E is a mixture of four vitamins called α, β, γ and δ tocopherols among which α tocopherol is the most active.
• Characteristics:
  • Light yellow fat soluble in oils.
  • Stable to heat and oxidation.
• Sources are cotton seed oil, maize oil, peanut oil and wheat germ oil.
• Deficiency causes damage to the reproductive system.

Hence, Vitamin E is also called tocopherol.

Additional Information 

• Riboflavin is vitamin B₂.
• Calciferol is vitamin D.
• Thiamine is vitamin B₁.

The correct answer is 8 minutes.

• It takes 8 minutes to reach the earth.

Key Points

• Light is a form of energy which is propagated as electromagnetic waves.
• In the spectrum of electromagnetic waves, it lies between the ultra-violet and infra-red region and has a wavelength between 3900 Å to 7800 Å.
• light behaves as wave and particle both. 
• Speed of light is maximum in vacuum and air (3×10⁸ m/s).
• It is a transverse wave.
• It takes 8 min 19 s to reach on the earth from the sun.
• The light reflected from the moon takes 1.28 s  to reach earth.

Additional Information

• Electromagnetic waves are transverse, hence light is a transverse wave.
• Wave nature of light explains rectilinear propagation, reflection, refraction, interference, diffraction and polarization of light. 
• Refractive Index of a medium is defined as the ratio of the speed of light in a vacuum to the speed of light in the medium. 
• Light is measured with two main alternative sets of units: radiometry consists of measurements of light power at all wavelengths, while photometry measures light with a wavelength.

The first two statements give information about payal, monika and Sonam. Information about kunal and monika cannot be determined.