IIT JEE Practice Question and Answer

Q: What is the number of digits in 333? Given that log3 = 0.47712? 5818 0

  • 1
    12
    Correct
    Wrong
  • 2
    13
    Correct
    Wrong
  • 3
    14
    Correct
    Wrong
  • 4
    15
    Correct
    Wrong
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Answer : 2. "13"
Explanation :

Answer: B) 13 Explanation:  Let   Let x=333 = 333    Then, logx = 33 log3     = 27 x 0.47712 = 12.88224    Since the characteristic in the resultant value of log x is 12   ∴The number of digits in x is (12 + 1) = 13    Hence the required number of digits in 333is 13.

Q: A sum of Rs. 427 is to be divided among A, B and C in such a way that 3 times A’s share, 4 times B’s share and 7 times C’s share are all equal. The share of C is ? 5812 0

  • 1
    64
    Correct
    Wrong
  • 2
    76
    Correct
    Wrong
  • 3
    84
    Correct
    Wrong
  • 4
    98
    Correct
    Wrong
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Answer : 3. "84"
Explanation :

Answer: C) 84 Explanation: Given total sum = Rs. 427And given that 3 times A’s share, 4 times B’s share and 7 times C’s share are all equal.=> 3A = 4B = 7CBut given=> A + B + C = 427Now express A and B in terms of C i.e=> (7C/3) + (7C/4) + C = 427=> C = 84

Q: A group of 10 representatives is to be selected out of 12 seniors and 10 juniors. In how many different ways can the group be selected if it should have at least one senior ? 5796 0

  • 1
    ²²C₁₀ + 1
    Correct
    Wrong
  • 2
    ²²C₉ + ¹⁰C₁
    Correct
    Wrong
  • 3
    ²²C₁₀
    Correct
    Wrong
  • 4
    ²²C₁₀ - 1
    Correct
    Wrong
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Answer : 4. "²²C₁₀ - 1"
Explanation :

Answer: D) ²²C₁₀ - 1 Explanation: The total number of ways of forming the group of ten representatives is ²²C₁₀. The total number of ways of forming the group that consists of no seniors is ¹⁰C₁₀ = 1 way The required number of ways = ²²C₁₀ - 1

Q: If today is Saturday, what will be the day 350 days from now  ? 5777 0

  • 1
    Saturday
    Correct
    Wrong
  • 2
    Friday
    Correct
    Wrong
  • 3
    Sunday
    Correct
    Wrong
  • 4
    Monday
    Correct
    Wrong
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Answer : 1. "Saturday"
Explanation :

Answer: A) Saturday Explanation: 350 days, 350/7 = 50, no odd days, so it will be a Saturday.

Q: Which is the gas used for making vegetables and vanaspathi from vegetable oils? 5759 0

  • 1
    Hydrogen
    Correct
    Wrong
  • 2
    Nitrogen
    Correct
    Wrong
  • 3
    Argon
    Correct
    Wrong
  • 4
    Helium
    Correct
    Wrong
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Answer : 1. "Hydrogen"
Explanation :

Answer: A) Hydrogen Explanation: Hydrogen gas is used for making vegetables and vanaspathi from vegetable oils. As it is colourless, odourless, tasteless, flammable gaseous substance, it is added to oils to make them more solid or spreadable. The use of hydrogenation helps to prolong the shelf life of the food and maintain flavour stability.

Q: The Study of Ancient Societies is called 5752 0

  • 1
    Anthropology
    Correct
    Wrong
  • 2
    Archaeology
    Correct
    Wrong
  • 3
    History
    Correct
    Wrong
  • 4
    Ethnology
    Correct
    Wrong
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Answer : 2. "Archaeology"
Explanation :

Answer: B) Archaeology Explanation: Archaeology is the science which studies ancient societies based on their material remains. Through the analysis of objects and those works constructed by ancient peoples, this science can arrive at conclusions about their culture and their ways of life. There are several branches of Archaeology as well as many tools relevant to this science.

Q: Lichens are the best indicator of 5736 1

  • 1
    Air pollution
    Correct
    Wrong
  • 2
    Sound pollution
    Correct
    Wrong
  • 3
    Noise pollution
    Correct
    Wrong
  • 4
    Water pollution
    Correct
    Wrong
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Answer : 1. "Air pollution"
Explanation :

Answer: A) Air pollution Explanation: 1. Lichens are plants that grow in exposed places such as rocks or tree bark.   2.  Lichens are widely used as environmental indicators or bio-indicators. They can be used as air pollution indicators, especially of the concentration of sulfur-di-oxide in the atmosphere.     3. They need to be very good at absorbing water and nutrients to grow there.

Q: Which of these relationships is true of an uncharged atom? 5727 0

  • 1
    The atomic mass is equal to the atomic number.
    Correct
    Wrong
  • 2
    The number of electrons is equal to the number of neutrons.
    Correct
    Wrong
  • 3
    The number of protons is equal to the number of electrons.
    Correct
    Wrong
  • 4
    The atomic mass is equal to the number of electrons.
    Correct
    Wrong
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Answer : 3. "The number of protons is equal to the number of electrons."
Explanation :

Answer: C) The number of protons is equal to the number of electrons. Explanation: The number of protons is equal to the number of electrons. That is the number of positive charges is equal to the number of negative charges.

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