IIT JEE प्रश्न और उत्तर का अभ्यास करें
8प्र: Two trains are moving in the same direction at 72 kmph and 36 kmph. The faster train crosses a girl sitting at window seat in the slower train in 32 seconds. Find the length of the faster train ? 5351 05b5cc6d8e4d2b4197774e769
5b5cc6d8e4d2b4197774e769- 1170 mfalse
- 2100 mfalse
- 3270 mfalse
- 4320 mtrue
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उत्तर : 4. "320 m"
व्याख्या :
Answer: D) 320 m Explanation: Relative speed = (72 - 36) x 5/18 = 2 x 5 = 10 mps.Distance covered in 32 sec = 32 x 10 = 320 m. The length of the faster train = 320 m.
प्र: Who translated Ramayana into Persian? 5347 05b5cc675e4d2b4197774c139
5b5cc675e4d2b4197774c139- 1Abdul Fazitrue
- 2Badaunifalse
- 3Isar Dasfalse
- 4Abdul Latiffalse
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उत्तर : 1. "Abdul Fazi"
व्याख्या :
Answer: A) Abdul Fazi Explanation: In 1574 Akbar started a Maktab Khana or a house of translation works in Fatehpur Sikri. He endorsed the work to a few officials to make translations of the Sanskrit books Rajatarangini, Ramayana and Mahabharata into the Persian language. In that officials, Abdul Fazi translated Ramayana into Persian.
प्र: Which of these relationships is true of an uncharged atom? 5338 05b5cc688e4d2b4197774c35a
5b5cc688e4d2b4197774c35a- 1The atomic mass is equal to the atomic number.false
- 2The number of electrons is equal to the number of neutrons.false
- 3The number of protons is equal to the number of electrons.true
- 4The atomic mass is equal to the number of electrons.false
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उत्तर : 3. "The number of protons is equal to the number of electrons."
व्याख्या :
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.
प्र: Lichens are the best indicator of 5313 15b5cc6ade4d2b4197774d0ff
5b5cc6ade4d2b4197774d0ff- 1Air pollutiontrue
- 2Sound pollutionfalse
- 3Noise pollutionfalse
- 4Water pollutionfalse
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उत्तर : 1. "Air pollution"
व्याख्या :
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.
प्र: Pen is to poet as needle is to 5295 05b5cc6a2e4d2b4197774cb84
5b5cc6a2e4d2b4197774cb84- 1Sewingfalse
- 2Threadfalse
- 3Tailortrue
- 4Buttonfalse
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उत्तर : 3. "Tailor"
व्याख्या :
Answer: C) Tailor Explanation: Here Pen is a tool which is used to write and poet uses it. Then, the needle is a tool which is used to stitch and it is used by Tailor. Except tailor, none of the other options is a person to use it. Hence, Pen : Poet :: Needle : Tailor
प्र: A person takes 20 minutes more to cover a certain distance by decreasing his speed by 20%. What is the time taken to cover the distance at his original speed ? 5275 05b5cc6eee4d2b4197774eebe
5b5cc6eee4d2b4197774eebe- 11hrfalse
- 21 hr 20 mintrue
- 31 hr 10 minfalse
- 450 minfalse
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उत्तर : 2. "1 hr 20 min"
व्याख्या :
Answer: B) 1 hr 20 min Explanation: Let the distance and original speed be 'd' km and 'k' kmph respectively. d/0.8k - d/k = 20/60 => 5d/4k - d/k = 1/3 => (5d - 4d)/4k = 1/3 => d = 4/3 k Time taken to cover the distance at original speed = d/k = 4/3 hours = 1 hour 20 minutes.
प्र: Two persons start running simultaneously around a circular track of length 300 m from the same point at speeds of 15 km/hr and 25 km/hr. When will they meet for the first time any where on the track if they are moving in opposite directions ? 5259 05b5cc6e5e4d2b4197774ecf2
5b5cc6e5e4d2b4197774ecf2- 127 sectrue
- 231 secfalse
- 323 secfalse
- 429 secfalse
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उत्तर : 1. "27 sec"
व्याख्या :
Answer: A) 27 sec Explanation: Time taken to meet for the first time anywhere on the track = length of the track / relative speed = 300 / (15 + 25)5/18 = 300x 18 / 40 x 5 = 27 seconds.
प्र: The average weight of 45 passengers in a bus is 52 kg. 5 of them whose average weight is 48 kg leave the bus and other 5 passengers whose average weight is 54 kg join the bus at the same stop. What is the new average weight of the bus? 5251 05b5cc6abe4d2b4197774d06c
5b5cc6abe4d2b4197774d06c- 154.21 kgsfalse
- 251.07 kgsfalse
- 352.66 kgstrue
- 453.45 kgsfalse
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उत्तर : 3. "52.66 kgs"
व्याख्या :
Answer: C) 52.66 kgs Explanation: Given total number of passengers in the bus = 45 First average weight of 45 passengers = 52 kgs Average weight of 5 passengers who leave bus = 48 Average weight of 5 passengers who joined the bus = 54 Therefore, the net average weight of the bus is given by = 45 x 52 - 5 x 48 + 5 x 5445 = 237045= 1583= 52.66 kgs.