IIT JEE Practice Question and Answer

Q: The probability that a number selected at random from the first 100 natural numbers is a composite number is  ? 1774 0

  • 1
    3/2
    Correct
    Wrong
  • 2
    2/3
    Correct
    Wrong
  • 3
    1/2
    Correct
    Wrong
  • 4
    34/7
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 1. "3/2"
Explanation :

Answer: A) 3/2 Explanation: The number of exhaustive events = 100 C₁ = 100. We have 25 primes from 1 to 100. Number of favourable cases are 75. Required probability = 75/50 = 3/2.

Q: Who invented Bifocal Lens? 1774 0

  • 1
    John Adams
    Correct
    Wrong
  • 2
    Benjamin Franklin
    Correct
    Wrong
  • 3
    James Madison
    Correct
    Wrong
  • 4
    Thomas Jefferson
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 2. "Benjamin Franklin"
Explanation :

Answer: B) Benjamin Franklin Explanation: Benjamin Franklin has long been credited with the invention of bifocal lenses and he was the first to wear bifocal lenses. He did not produce them himself but instead had some optician in London or France make them for him to overcome Presbyopia, a condition that Franklin suffered. He was tired switching between lenses for far and near sightedness. And that resulted in inventing Bifocal Lenses.

Q: How many feet are in a meter? 1774 0

  • 1
    3.214
    Correct
    Wrong
  • 2
    3.28084
    Correct
    Wrong
  • 3
    3.2516
    Correct
    Wrong
  • 4
    3.21456
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 2. "3.28084"
Explanation :

Answer: B) 3.28084 Explanation: We know that,  1 meter = 100 cms.  => 1 meter = 3.28084 feet.

Q: Which planet has the lowest density? 1773 0

  • 1
    Earth
    Correct
    Wrong
  • 2
    Jupiter
    Correct
    Wrong
  • 3
    Saturn
    Correct
    Wrong
  • 4
    Neptune
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 3. "Saturn"
Explanation :

Answer: C) Saturn Explanation: Saturn, the solar system's second largest planet that takes the prize for least dense. It's less dense than water, which has led many people to postulate that it would float. However, even if it somehow found its way to a body of water large and deep enough to contain it, Saturn would break apart and its rocky core would sink.

Q: Name the company that has recently created the world’s smallest magnet using a single atom which can store one bit of data on it. 1773 0

  • 1
    TCS
    Correct
    Wrong
  • 2
    Microsoft
    Correct
    Wrong
  • 3
    IBM
    Correct
    Wrong
  • 4
    Infosys
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 3. "IBM"
Explanation :

Answer: C) IBM Explanation: A team of researchers at IBM has created the world’s smallest magnet using a single atom which can store one bit of data on it.

Q: Metals are good conductors of electricity because 1773 0

  • 1
    The atoms are lightly packed
    Correct
    Wrong
  • 2
    They contain free electrons
    Correct
    Wrong
  • 3
    They have high melting point
    Correct
    Wrong
  • 4
    All the above
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 2. "They contain free electrons"
Explanation :

Answer: B) They contain free electrons Explanation: Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity. Because the electrons in the atom's higher energy levels can separate from the atoms easily, they can be pulled out with very little energy. Because the molecular structure of the metal is such that 'free electrons' are free to move, thus being categorized as electrically conductive.   For example, copper is used for electrical wiring because it is a good conductor of electricity.

Q: Fog is an example of a 1773 0

  • 1
    liquid dispersed in gas
    Correct
    Wrong
  • 2
    solid dispersed in liquid
    Correct
    Wrong
  • 3
    liquid dispersed in solid
    Correct
    Wrong
  • 4
    gas dispersed in liquid
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 1. "liquid dispersed in gas"
Explanation :

Answer: A) liquid dispersed in gas Explanation: Fog is an example of a colloidal system liquid dispersed in gas.

Q: Wild animals are not considered a natural resource. 1772 0

  • 1
    TRUE
    Correct
    Wrong
  • 2
    FALSE
    Correct
    Wrong
  • Show AnswerHide Answer
  • Workspace

Answer : 2. "FALSE"
Explanation :

Answer: B) FALSE Explanation: The given statement is False. Wild animals are considered as a natural resource. Natural resources are resources taken from nature to satisfy our needs. These natural resources are: 1) Air 2) Water 3) Soil 4) Plants 5) Animals 6) Minerals 7) Forests 8) Natural Gas 9) Coal 10) Petroleum.

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully

      Report Error

    Please Enter Message
    Error Reported Successfully