GATE Practice Question and Answer

Q: Which of these molecules are polar? Check all that apply. 1900 0

  • 1
    SO2
    Correct
    Wrong
  • 2
    CH2Cl2
    Correct
    Wrong
  • 3
    PCl3
    Correct
    Wrong
  • 4
    All the above
    Correct
    Wrong
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Answer : 4. "All the above"
Explanation :

Answer: D) All the above Explanation:    1) SO2                  2) CH2Cl2                3) PCl3 How to check the given molecules are polar or non polar : If the electronegativity of the two bonded atoms are different then the bond is polar. Although, some molecules contain polar bonds, the molecule may be non-polar. If the polarity of all the bonds present in the molecule are cancel each other then molecule is non-polar.   In the given options, SO2  is polar because the dipole moments on the O do not cancel. PCl3  is polar because the P-Cl bonds do not cancel out. CH2Cl2  polar because the C-Cl bonds do not cancel.   Hence, in brief, Polar molecules are molecules with net dipole due to the presence of partial positive and partial negative charge. For example, water is a polar molecule that has partial positive and partial negative charge on it. CO2 is a non polar compound.   Therefore, all the given options SO2, CH2Cl2 and PCl3 are Polar molecules.

Q: Which one of the following is not a prime number? 1899 0

  • 1
    91
    Correct
    Wrong
  • 2
    71
    Correct
    Wrong
  • 3
    41
    Correct
    Wrong
  • 4
    31
    Correct
    Wrong
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Answer : 1. "91"
Explanation :

Answer: A) 91 Explanation: Prime Numbers :: Numbers which are divisible by only 1 and itself are Prime Numbers.   It's answer will be 91. Because 91 can be divisible by 7,13,91,1. It is quite clear that prime number should be divisible only by itself and by 1.

Q: Simplify 39.96% of 649.85 ÷13.07 = 45.14 - ? 1899 0

  • 1
    25
    Correct
    Wrong
  • 2
    26
    Correct
    Wrong
  • 3
    27
    Correct
    Wrong
  • 4
    28
    Correct
    Wrong
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Answer : 1. "25"
Explanation :

Answer: A) 25 Explanation: This can be easily simplified by Approximation process Given 39.96% of 649.85 ÷13.07 = 45.14 - ? can be written as  40% of 650 ÷13 = 45 - ?   40 x 65010013 = 45 - ?? = 45 - 20? = 25.

Q: Is Air a Mixture? 1899 0

  • 1
    TRUE
    Correct
    Wrong
  • 2
    FALSE Answer & Explanation Answer:
    Correct
    Wrong
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Answer : 1. "TRUE"
Explanation :

Answer: A) TRUE Explanation: True, Air is a Mixture. Air is considered as mixture for the following reasons ; 1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air. 2. Air shows the properties of all the gases present in the atmosphere. For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion. 3. Air does not have a fixed formula. 4. Air has a variable composition because air at different places contains different amount of gases. 5. Heat or Light energy is neither absorbed nor released when air is prepared physical by mixing required amount of gases . 6. Mixture does have fixed boiling Point. It holds good in case of liquid air.

Q: Four person A, B, C and D. The sum of their present age is 176. Four years ago ratio of their age was 11: 9 : 6 : 14, then find who is eldest and youngest among them ? 1898 0

  • 1
    A is eldest & C is youngest
    Correct
    Wrong
  • 2
    D is eldest & C is youngest
    Correct
    Wrong
  • 3
    C is eldest & A is youngest
    Correct
    Wrong
  • 4
    A is eldest & B is youngest
    Correct
    Wrong
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Answer : 2. "D is eldest & C is youngest"
Explanation :

Answer: B) D is eldest & C is youngest Explanation: Given sum of present ages of A, B, C & D A + B + C + D = 176 and also given that, (A-4) : (B-4) : (C-4) : (D-4) = 11 : 9 : 6 : 14 Let the ratio = x => A-4 + B-4 + C-4 + D-4 = 11x + 9x + 6x + 14x => (A + B + C + D ) - 16 = 40x => 176 - 16 = 40x => x = 4 => A = 44 + 4 = 48 => B = 40 => C = 28 => D = 60 Therefore, from the above conclusions D is eldest with 60 years and C is youngest with 28 years of ages.

Q: CTRL + ] is used for 1896 0

  • 1
    Re-do
    Correct
    Wrong
  • 2
    Right align text
    Correct
    Wrong
  • 3
    Increase in font size
    Correct
    Wrong
  • 4
    Expand or collapse the ribbon
    Correct
    Wrong
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Answer : 3. "Increase in font size"
Explanation :

Answer: C) Increase in font size Explanation: CTRL + ] is a computer shortcut and is used for Increase in font size.   Shortcuts : Re-do ---- Ctrl + Y Right align text ---- Ctrl + R Expand or collapse the ribbon ---- Ctrl + F1

Q: Crack the Logical #MathPuzzle? 1896 0

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Answer :
Explanation :

From given data, Rs. 1 = 40 strawberries => Rs. 2 = 80 strawberries Rs. 5  = 1 apple => Rs. 95 = 19 apple. Rs. 3 = 1 mango => Rs. 3 = 1, mango Now, Total So 100 Rs = 100 Fruits.

Q: If the average height of boys in a hall is 180 cm and that of girls is 150 cm. If the average height of the gathering is 165 cm, then find the number of girls present in the hall if the number of boys present in the hall are 78 ? 1895 0

  • 1
    56
    Correct
    Wrong
  • 2
    64
    Correct
    Wrong
  • 3
    87
    Correct
    Wrong
  • 4
    78
    Correct
    Wrong
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Answer : 4. "78"
Explanation :

Answer: D) 78 Explanation: Using Trial and error method, we get the number of girls in the hall = 78

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