IIT JEE प्रश्न और उत्तर का अभ्यास करें
8प्र: In a vacuum, all electromagnetic waves have the same 1547 05b5cc63de4d2b4197774bb0a
5b5cc63de4d2b4197774bb0a- 1Velocitytrue
- 2Wavelenthfalse
- 3Frequencyfalse
- 4All the abovefalse
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उत्तर : 1. "Velocity"
व्याख्या :
Answer: A) Velocity Explanation: When traveling in a vacuum, electronic waves from the electromagnetic spectrum all travel at the same speed. Velocity is speed with direction, so they would all travel at the same velocity, realtively speaking. But frequency and wavelength are quite different.
प्र: A is three times as old as B. C was twice-as old as A four years ago. In four years' time, A will be 31. What are the present ages of B and C ? 1547 05b5cc720e4d2b4197774f5ea
5b5cc720e4d2b4197774f5ea- 145, 10false
- 210, 50false
- 39, 50true
- 450, 15false
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उत्तर : 3. "9, 50"
व्याख्या :
Answer: C) 9, 50 Explanation: Let the age of A = A, B = B and C = C From given A = 3B 4 years ago, C-4 = 2(A-4); After 4 years A + 4 = 31; A = 27;sub in above B, we get B = 9 C = 2(27 - 4) + 4 = 46 + 4 = 50 Hence B = 9yrs and C = 50yrs.
प्र: Prasanna invested certain amount in three different schemes X, Y and Z with the rate of interest 10% p.a, 12% p.a and 15% p.a respectively. If the total interest accrued in one year was Rs. 3200 and the amount invested in Scheme Z was 150% of the amount invested in Scheme X and 240% of the amount invested in Scheme Y, what was the amount invested in Scheme Y by Prasanna ? 1546 05b5cc6c5e4d2b4197774ddb9
5b5cc6c5e4d2b4197774ddb9- 1Rs.6000false
- 2Rs.4500false
- 3Rs.7500false
- 4Rs.5000true
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उत्तर : 4. "Rs.5000"
व्याख्या :
Answer: D) Rs.5000 Explanation: Let a, b and c be the amounts invested in schemes X, Y and Z respectively. Then, As we know: Simple interest (S.I.) = PTR/100 (a × 10 × 1/100) + (b × 12 × 1/100) + (c × 15 × 1/100) = 3200 = 10a + 12b + 15c = 320000 .........(1) Now, c = 240% of b = 12b/5 .........(2) And, c = 150% of a = 3a/2 => a = 2/3 c = (2 × 12)b/(3 × 5) = 8b/5 .......(3) From (1), (2) and (3), we have 16b + 12b + 36b = 320000 => 64b = 320000 => b = 5000 ∴ Sum invested in Scheme Y = Rs.5000.
प्र: The price of an article has been reduced by 35%. In order to restore the original price the new price must be increased by ? 1546 05b5cc6dfe4d2b4197774eae4
5b5cc6dfe4d2b4197774eae4- 151.8 %false
- 249.25 %false
- 347.2 %false
- 453.84 %true
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उत्तर : 4. "53.84 %"
व्याख्या :
Answer: D) 53.84 % Explanation: 100 65 -------65 ------- 35100 ------ ? => 53.84 %
प्र: Math Logic Challenge 1546 05b5cc6d3e4d2b4197774e4b4
5b5cc6d3e4d2b4197774e4b4- 123false
- 226true
- 313false
- 429false
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उत्तर : 2. "26"
व्याख्या :
Answer: B) 26 Explanation: Let the integer be x. Then, x2-20x = 156 (x + 6)(x - 26) = 0 x = 26 The integer is 26.
प्र: Which of these illustrates the Secondary Structure of a Protein? 1545 05b5cc6abe4d2b4197774d02a
5b5cc6abe4d2b4197774d02a- 1Afalse
- 2Btrue
- 3Cfalse
- 4Dfalse
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उत्तर : 2. "B"
व्याख्या :
Answer: B) B Explanation: The Secondary Structure of a Protein is option B) The Secondary Structure of a Protein results from Hydrogen Bonds.
प्र: 100 percent of which number is 20? 1545 05b5cc6b0e4d2b4197774d28d
5b5cc6b0e4d2b4197774d28d- 1100false
- 2500false
- 320true
- 40false
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उत्तर : 3. "20"
व्याख्या :
Answer: C) 20 Explanation: Let the rquired number be 'P' According to the question, 100 x P100 = 20=> P = 20 x 100100 = 20 Hence, 100 percent of the number 20 is 20. Now, you can also try for 20 percent of what number is 100 20 x P100 = 100=> P = 100 x 10020 = 500=> P = 500 Hence, 20 percent of the number 500 is 100.
प्र: The area of a square is 1024 sq.cm. What is the ratio of the length to the breadth of a rectangle whose length is twice the side of the square and breadth is 12 cm less than the side of this square ? 1544 05b5cc72ce4d2b4197774f76e
5b5cc72ce4d2b4197774f76e- 114:9false
- 213:12false
- 316:5true
- 417:13false
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उत्तर : 3. "16:5"
व्याख्या :
Answer: C) 16:5 Explanation: Area of a square SxS = 1024 => S = 32 cmLength of the rectangle = 32x2 cm = 64 cmBreadth of the rectangle = 32 - 12 = 20 cmRequired ratio = 64 : 20 = 16 : 5

