IIT JEE Practice Question and Answer

Q: What happens when two atoms form a chemical bond? 1392 0

  • 1
    Two atoms fuse together to form a chemical bond
    Correct
    Wrong
  • 2
    The atoms share or transfer electrons
    Correct
    Wrong
  • 3
    A chemical bond forms when two atoms transfer or share protons to achieve a stable nucleus
    Correct
    Wrong
  • 4
    Like charges in the atoms cause them to stick together
    Correct
    Wrong
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Answer : 2. "The atoms share or transfer electrons"
Explanation :

Answer: B) The atoms share or transfer electrons Explanation: All chemistry is based on sharing electrons. A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells.

Q: What time of year do squirrels build nests? 1392 0

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    Winter
    Correct
    Wrong
  • 2
    Summer
    Correct
    Wrong
  • 3
    Rainy
    Correct
    Wrong
  • 4
    Monsoon
    Correct
    Wrong
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Answer : 2. "Summer"
Explanation :

Answer: B) Summer Explanation: Squirrels typically build leaf nests in the summer by weaving together small branches they've gnawed off of trees. These nests are lined with grass, moss, leaves and pine needles. Both male and female gray squirrels of all ages participate in building dens.

Q: Google has introduced a new app named what that allows anybody to submit stories for and about their communities? 1391 0

  • 1
    Bulletin
    Correct
    Wrong
  • 2
    Allo
    Correct
    Wrong
  • 3
    FastRead
    Correct
    Wrong
  • 4
    Google Express
    Correct
    Wrong
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Answer : 1. "Bulletin"
Explanation :

Answer: A) Bulletin Explanation:

Q: What is the bond order of O2? 1391 0

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    1.5
    Correct
    Wrong
  • 2
    2
    Correct
    Wrong
  • 3
    2.5
    Correct
    Wrong
  • 4
    1
    Correct
    Wrong
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Answer : 2. "2"
Explanation :

Answer: B) 2 Explanation: The number of bonds between a pair of atoms is called the bond order. Bond orders can be calculated from Lewis structures, which are the heart of the valence-bond model. Oxygen, for example, has a bond order of two. When there is more than one Lewis structure for a molecule, the bond order is an average of these structures. The bond order in sulfur dioxide, for example, is 1.5  the average of an S-O single bond in one Lewis structure and an S=O double bond in the other. In molecular orbital theory, we calculate bond orders by assuming that two electrons in a bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O2 molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in antibonding molecular orbitals in the electron configuration of this molecule. Thus, the bond order is two.

Q: Hemavathi gets 3 marks for each right sum and loses 2 marks for each wrong sum. He attempts 35 sums and obtains 60 marks. The number of sums attempted correctly is ? 1390 0

  • 1
    23
    Correct
    Wrong
  • 2
    24
    Correct
    Wrong
  • 3
    25
    Correct
    Wrong
  • 4
    26
    Correct
    Wrong
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Answer : 4. "26"
Explanation :

Answer: D) 26 Explanation: Let, Hema attempted 'k' sum correctly, then k x 3 -2 x(35-k) = 605k = 130k = 26 so 26 correct sums.

Q: The breadth of a rectangular field is 75% of its length. If perimeter of the field is 1050 m, what will be th area of field ? 1388 0

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    65700 sq.m
    Correct
    Wrong
  • 2
    54500 sq.m
    Correct
    Wrong
  • 3
    78700 sq.m
    Correct
    Wrong
  • 4
    67500 sq.m
    Correct
    Wrong
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Answer : 4. "67500 sq.m"
Explanation :

Answer: D) 67500 sq.m Explanation: Let the length be 'l' and breadth be 'b'. b = l × 3/4__________(a) 2(l+b) = 1050 l+b = 525___________(b) From equations (a) and (b), l = 300m, b = 225 m Area = l × b = 300 × 225 = 67500 sq.m.

Q: Where are chromatids found in a cell? 1388 0

  • 1
    Anaphase
    Correct
    Wrong
  • 2
    Metaphase
    Correct
    Wrong
  • 3
    Prophase
    Correct
    Wrong
  • 4
    None of the above
    Correct
    Wrong
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Answer : 2. "Metaphase"
Explanation :

Answer: B) Metaphase Explanation: A chromatid is one copy of a newly copied chromosome which is still joined to the original chromosome by a single centromere. The two identical copies—each forming one half of the replicated chromosome are called chromatids. Chromonema is the fibre-like structure in prophase in the primary stage of DNA condensation. In metaphase, they are called chromatids.

Q: The inherited traits of an organism are controlled by 1388 0

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    DNA
    Correct
    Wrong
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    Enzymes
    Correct
    Wrong
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    Nucleotides
    Correct
    Wrong
  • 4
    RNA
    Correct
    Wrong
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Answer : 1. "DNA"
Explanation :

Answer: A) DNA Explanation: The inherited traits of an organism are controlled by DNA molecules.   The traits an organism displays are ultimately determined by the genes it inherited from its parents, in other words by its genotype. Animals have two copies of all their chromosomes, one from each parent.

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