Question Discussion & Solution

1) Lalit scored 72 marks in 100-mark test.

Shubham scored 8 marks more than Lalit but 6 marks less than Sunil.

Thus, Shubham’s marks = 72 + 8 = 80

Sunil’s marks = 80 + 6 = 86

Therefore, Lalit < Shubham < Sunil.

2) Ravi scored 6 marks less than Daniel, and 7 marks more than Sunil.

Ravi’s marks = Sunil’s marks + 7

Daniel’s marks = Ravi’s marks + 6

Thus, Sunil < Ravi < Daniel.

Now, we have the following order:

Lalit < Shubham < Sunil < Ravi < Daniel

Second lowest = second in ascending order.

Concept:

• Atoms are made up of subatomic particles - electrons protons and neutrons.
• In the center of an atom, a nucleus is present which contains protons and neutrons together known as nucleons.
• The mass of an atom is most concentrated at the center of the atom, i.e. the nucleus.

​Electrons:

• Discovered by Sir J.J Thomson in the year 1897.
• Previously named as cathode rays as they were supposed to be emitted from the cathode.
• They are deflected towards the positive side.
• They have high kinetic energy.
• They are deflected by an electric and magnetic field.
• It has a negative charge of

  \(charge=1.602\times10^{-19} coulombs \)
\(mass={1\over 1837}\times 9.107\times 10^{-28}g\)

Protons:

• Discovered by Goldstein.
• Depicted first as positive rays because it seemed to emerge from the anode.
• Mass of a proton is

 \(1.670 \times 10^{- 24}g\)

\(Charge=1.602\times 10^{-19} coulombs\)​

Explanation:

• Rutherford's discovery led to the discovery of nucleus.
• He found out that most of the mass of the nucleus is situated in its centre and contains the positively charged particles protons.
• The atom is otherwise empty and as electrons have negligible mass, the mass of an atom should be equal to the sum of mass of protons present in it.
• However, it was seen that in Helium, there are only two protons, so its mass should be twice the mass of each proton = \(2\times 1.008 a.m.u\).
• Experimental results revealed that it has a mass of 4.003a.m.u.
• Hence, it was concluded that the nucleus has particles containing no charge but mass almost equal to that of a proton.
• This was established by scientist James chadwick in 1932.

Additional Information

Rutherford's gold foil experiment: 

• He discovered the atomic nucleus and gave us an atomic model.
• He directed alpha particles towards a metal sheet.
• He saw that most of the alpha particles, which are positively charged particles, are not getting deflected.
• Most of the alpha particles emerged undeflected.

• Therefore, he concluded that most of the mass of the nucleus is situated in its centre and contains the positively charged particles protons.
• Electrons revolve around the nucleus in certain orbits.

The correct answer is Femur.

Key Points

• The largest bone in the human body is the femur, the thighbone.
• It is the largest, longest, and strongest bone in the human body.
• The femur runs from the keen to the hip.
• The Femur or thigh bone is the largest and heaviest bone in the human body.
• At the proximal end of the Femur, there is a rounded prominence which is called the Head of the Femur.
• The femur runs from the keen to the hip.
• It carries all the upper body weight.
• The other parts of the leg are the tibia, femur, fibula, and keep cap also known as patella.

Additional Information

• The human skeleton is made up of 206 bones, including bones of the
  • Skull:  including the jaw bone (mandible, maxilla)
  • Spine: cervical, thoracic and lumbar vertebrae, sacrum and tailbone (coccyx)
  • Chest: ribs and breastbone (sternum)
  • Arms: the shoulder blade (scapula), collar bone (clavicle), radius, humerus and ulna
  • Hands: wrist bones (carpals), metacarpals and phalanges
  • Pelvis: hip bones
  • Legs: the thigh bone (femur), the kneecap (patella), shin bone (tibia) and fibula
  • Feet: tarsals, metatarsals, and phalanges.

The correct answer is Lead and Tin.

Key Points

• Soldering is the process of joining two metal objects together by a third soft metal alloy which is called solder.
• Solder is a metal alloy that melts at a lower temperature than the metals being soldered.
• A commonly used alloy is solder, which is an alloy of tin (Sn) and lead (Pb).
• The alloy of tin-lead solder is a mixture of 63% tin and 37% lead. 63/37 solder melts at 183°C.
• So, Alloy of tin (Sn) and lead (Pb) is used for welding electrical wire together.

Additional Information

• Element Tin (Sn) belongs to Group 14 of the periodic table.
  • Atomic Number - 50
  • Atomic Mass  - 118.710 amu.
• Element Lead (Pb) belongs to Group 14.
  • Atomic Number - 82
  • Atomic Mass - 207.2 amu.

The correct answer is Bullets.

Key Points

• When data is in list format Bullets can be used to represent it neatly in MS Word.
• Microsoft products allow you to organize content using bulleted and numbered lists.
  • You can also create customized lists by editing the bullet/number font, color, alignment, and icon style. 
• Within your Microsoft document, place your cursor or highlight the text where you wish to insert a bulleted list. 
• Under the [Home] tab in the “Paragraph” section, click the [Bullets] drop-down menu. 
• Choose a bullet style or select "Bullets and Numbering” to create a customized bullet style.
• To change the alignment of the bulleted list, from the "Paragraph" section, click the [Aligh Text] drop-down menu.
• 

Additional Information

• Change Case
  • You can also capitalize a character you are typing by pressing and holding the SHIFT key while you type.
  • You can also press the CAPS LOCK to have every letter that you type capitalized, and then press the CAPS LOCK again to turn off capitalization.
  • 
• Spacing between Lines
  • Following are the simple steps to adjust the spacing between two lines of the document.
  • Step 1
    • Select the paragraph or paragraphs for which you want to define the spacing.
    • You can use any of the text selection methods to select the paragraph(s).
  • Step 2
    • Click the Line and Paragraph Spacing Button triangle to display a list of options to adjust the space between the lines.
    • You can select any of the options available by simply clicking over them.
  •