Question Discussion & Solution

The Correct Answer is 24.

Key Points

• Human ribs are flat bones that form part of the rib cage to help protect internal organs.
• Humans usually have 24 ribs, in 12 pairs.
• The first seven pairs are attached directly to the sternum by costal cartilages and are called true ribs.
• The 8th, 9th, and 10th pairs are called false ribs, they do not join the sternum directly but are connected to the 7th rib by cartilage.

Additional Information 

• Human ribs are flat bones that form part of the rib cage to help protect internal organs.
• Humans usually have 24 ribs, in 12 pairs.
• Only 1 in 500 people have an extra rib known as a Cervical rib. 
• At the front of the body, most of the ribs are joined by costal cartilage to the sternum.
• Ribs connect to vertebrae at the costovertebral joints.

The correct answer is citric.

• Orange juice contains citric acid due to which tastes sour.

Key Points

• Fruits that contain citric acid are called citrus fruits.
• Citrus fruits are lemon, lime, orange, Grapefruit, etc.
• The formula of citric acid is C₆H₈O₇.

Additional Information

• Oxalic acid is found in tomato.
  • Its formula is C₂H₂O₄.
• Formic acid is found in the sting of ants and bees.
  • Its formula is CH₂O₂.
• Acetic acid is found in vinegar.
  • Its formula is id CH₃COOH.

Concept:

ER model describes data as entities, relationships, and attributes. It is a high-level conceptual data model. This model is used to define the data elements and relationships for a specified system.

Entity:

The entity is a thing in the real world with an independent existence. An entity may be an object with physical existence. For example particular person, car or it may be an object with a conceptual existence For example company, job, etc.

Attributes:

Each entity has attributes – the particular properties that describe it.

Relationship:

It is used to describe the relation between two entities.

Explanation:

E-R Diagram is design level task and Relational model is implementation.

The relational model is implemented from E-R Diagram and in this, it gets rid of the multivalued attributes.

Relations produced from the E - R Model will always be in 1NF, that is, Simple atomic values with non-multivalued attributes.

NOTES:

Concept:

• Potential Energy: The energy of an object obtained by doing work against the conservative forces like spring force and gravitational force is called potential energy.
• The Gravitational potential energy of an object at a height h from the ground is given as

P = mgh

The spring potential energy of spring when it is stretched x distance from its natural length is given as

 \(P = \frac{1}{2}kx^2\)

• Kinetic Energy: The energy obtained by an object by virtue of its motion is called kinetic energy.

\(K = \frac{1}{2}mv^2\)

K is kinetic energy, v is the speed of the object, m is the mass of the object.

• Mechanical Energy: The sum of potential energy and kinetic energy is called mechanical energy.

Explanation:

So, from the above concept, it is clear that total mechanical energy is the sum of potential energy and kinetic energy. 

So, the answer is the Sum of Kinetic Energy and Potential Energy.

The correct answer is ​CTRL + Z.

• CTRL + Z is used to undo changes (UNDO) in Ms-Word.

​Key Points

• CTRL + Z
  • To reverse the last action done by can be regained using CTRL+Z shortcut.
  • We can reverse more than one action using this shortcut tool.

Additional Information

• CTRL + Y
  • The keyboard shortcut for Redo is CTRL-Y.
• ​​Ctrl+N
  • ​​Ctrl+N is a keyboard shortcut most often used to create a new document, window, workbook, or other types of file.
• CTRL + H
  • Ctrl+H is a keyboard shortcut whose function varies depending on the program.
  • For example, with text editors, Ctrl+H is used to find and replace a character, word, or phrase.
  • In an Internet browser, Ctrl+H opens the history tool.