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Questions and Answers
4081. The angle in which a cricket ball should be hit to travel max. horizontal distance is:
A
60° with horizontal
B
30° with horizontal
C
15° with horizontal
D
45° with horizontal
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Answer & Explanation
Answer : Option D
Explanation :
45° with horizontal.This has to do with the equation of a parabola or trajectory which is z = (tanq)x – q 2 (cos) q x 2. We can see that if the ball is fired at a 45 degree angle from the ground, the horizontal distance will be a maximum.
4082. Which among the given is a radioactive element -
A
Chromium
B
Cobalt
C
Uranium
D
Argon
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Answer & Explanation
Answer : Option C
Explanation :
Uranium.Uranium (U) is a naturally occurring radioactive element. One of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear fission reaction. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable ar- rangement.In fact, uranium was the element that made the discovery of radioactivity possible.
4083. Synthetic detergents are prepared from
A
glycerides
B
potassium salts of higher fatty-acids
C
hydrocarbons of petroleum
D
sodium salts of higher fattyacids
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Answer & Explanation
Answer : Option C
Explanation :
hydrocarbons of petroleum.Synthetic detergents are prepared from hydrocarbons of petroleum. Calcium & magnesium salts of detergents are soluble in water. They are sodium salts of a long chain benzene sulphonic acids or sodium salts of long chain alkyl hydrogen sulphates. So cleansing action of detergents remain unaffected in hard water.
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