This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is a catalyst? |
|
Answer» A catalyst is a substance which when added to a reacting system, increases the rate of a reaction without itself undergoing any permanent chemical change. |
|
| 2. |
In Haber process for manufacture of NH3, the catalyst used is …………… (A) iron (B) copper (C) vanadium pentoxide (D) nickel |
|
Answer» Correct option is (A) iron |
|
| 3. |
What is basic structural unit of orthoboric acid? Name type of bond present in them. |
|
Answer» BO33- is basic structural unit of boric acid. Covalent bonds are present. |
|
| 4. |
`H_2SO_4` cannot be used for obttaining HBr from KBr because :A. (1) HBr oxidises `H_2SO_4`.B. (2) HBr reduces `H_2SO_4`C. (3) HBr undergoes disproportionationD. (4) KBr reacts very slowly. |
|
Answer» Correct Answer - B The HBr so formed reduces `H_2SO_4` and itself gets oxidised to evolve `Br_2`. `2HBr+H_2SO_4 to 2H_2O + SO_2 + Br_2` |
|
| 5. |
Name the scientist who discovered Neutrons. |
|
Answer» J. Chadwik discovered Neutrons. |
|
| 6. |
Which of the following is the weakest acid?A. (1) HFB. (2) HCIC. (3) HBrD. (4) HI |
|
Answer» Correct Answer - A Acid strength order : HI gt HBr gt HCl gt HF Amongs these HI , HBr, HCl are strong acids whereas HF is a weak acid |
|
| 7. |
Among the following which reaction is not correct:A. `NaAlO_2 + HCl + H_2O to NaCl + Al(OH)_3`B. `Ca_3N_2 + HCl to CaCl_2 + NH_3`C. `Au + H + NO_3^(-) + Cl^(-) to AuCl_3^(-) + NO +H_2O`D. `Pt + H^(+) + NO_3^(-) + Cl^(-) to PtCl_6^(2-) + NO + H_2O` |
|
Answer» Correct Answer - C `Au+H^(+) + NO_3^(-) + Cl^(-) to AuCl_4^(-) + NO + H_2O` |
|
| 8. |
Order of boiling point is:A. (1)HF gt Hl gt HBrgt HClB. (2)HFgt HBrgtHI gt HCIC. (3) HCI gt HBr gt HI gt HFD. (4) HCI gt HI gt HBr gt HF |
|
Answer» Correct Answer - A `BP uarr` with increase in atomic mass of the hologes. HF has highest BP due to association of HF molecule through H-bonding . |
|
| 9. |
What is valancy? |
|
Answer» The combining capacity of an element is called the valency. |
|
| 10. |
Name the scientist who proposed about electrons. |
|
Answer» J.J. Thomson. |
|
| 11. |
Name the moderator used in a nuclear reactor. |
| Answer» The moderator used in a nuclear reactor is Graphite. | |
| 12. |
What do you think is the purpose of the thick, concrete chamber surrounding the reactor of a nuclear power plant ? |
| Answer» Thick concrete chamber is required to prevent the radioactive rays to travel outside | |
| 13. |
Which amongst the following changes are exothermic or endothermic in nature?i. Decomposition of ferrous sulphateii. Dilution of sulphuric acidiii. Dissolution of sodium hydroxide in wateriv. Dissolution of ammonium chloride in water. |
|
Answer» i. Endothermic ii. Exothermic iv. Endothermic |
|
| 14. |
When potassium nitrate is heated, it decomposes into potassium nitrite and oxygen. Write a balanced equation for this reaction and add the state symbols of the reactants and products.2KNO3 (s) —–> 2KNO2 (s) + O2 (g) |
|
Answer» (a) Oxidation; reduction. (b) Reduction; oxidation. (c) Rancidity. |
|
| 15. |
The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps burn other things. (a) What is compound A ? (b) What is compound B ? (c) What is gas C ?(d) What do you think is the black substance X ? What is its function ? (e) What is the general name of substances like X ? |
|
Answer» (a) Potassium chlorate, KClO3 (b) Potassium chloride, KCl (c) Oxygen, O2 (d) Manganese dioxide, MnO2 ; It acts as a catalyst in the decomposition of potassium chlorate to form oxygen gas (e) Catalysts |
|
| 16. |
How does Newton's third law of motion help us in walking? |
|
Answer» When we push the ground with our foot, the reaction of the ground pushes us forward. |
|
| 17. |
Give scientific reason:It takes time for pieces of Shahabud tile to disappear in HCl, but its powder disappears rapidly. |
|
Answer» The rate of a reaction depends upon the size of the particles of the reactants taking part in the reaction. The smaller the size of the reactants particles, the more is their total surface area and the faster is the rate of reaction. In the reaction of dil. HCl with pieces of Shahabad tile, CO2 effervescence is formed amid the tile disappears slowly. On the other hand. CO2 effervescence forms at faster rate with Shahabad tile powder and it disappears rapidly. |
|
| 18. |
(a) Name two systems which taken together perform the functions of control and coordination in human beings. (b) What does the central nervous system in humans consist of ? What is the job of the central nervous system ? (c) Give the various functions of brain. |
|
Answer» (a) Nervous system and endocrine system. (b) The central nervous system consists of the brain and spinal cord. The work of the CNS is to direct incoming messages to the motor neurons that are connected to the part of the body which will respond to a stimulus. It is involved in complicated responses where both (brain and spinal cord) work. It enables a person to give a more appropriate and more intelligent response to various situations. (c) (i) The brain receives information carrying nerve impulses from all the sensory organs of the body. (ii) It responds to the impulses brought in by sensory organs by sending its own instructions through motor nerves to the muscles and glands causing them to function accordingly. (iii) It correlates the various stimuli from different sense organs and produces the most appropriate and intelligent response. (iv) It coordinates the body activities so that the mechanisms and chemical reactions of the body work together efficiently. (v) It stores information so that behavior can be modified according to the past experience. |
|
| 19. |
What is the difference between a reflex action and walking? |
|
Answer» Walking is a voluntary activity but reflex action is involuntary activity. |
|
| 20. |
Mexico was conquered by A) Vasco da Gama B) Cortez C) Leopold II D) Darwin |
|
Answer» Mexico was conquered by Cortez |
|
| 21. |
“The congo free state” was established by A) Stanley B) Leopold-II C) Henry D) Ford |
|
Answer» (B) Leopold-II |
|
| 22. |
The English established political control over India in A) 1857 B) 1850 C) 1885 D) 1757 |
|
Answer» The English established political control over India in 1757 |
|
| 23. |
When India came to be directly ruled by the queen of English? |
|
Answer» In 1857 India came to be directly ruled by the queen of English. |
|
| 24. |
Who formulated the Munroe Doctrine? |
|
Answer» The President of the USA formulated ‘the Munroe Doctrine. |
|
| 25. |
When England colonised most of India? |
|
Answer» England was successful in colonizing most of India by 1757 . |
|
| 26. |
A hard material X which is mined from the earth is used as a household fuel and also for the generation of electricity at Thermal Power Stations. A soft material Y is also used as a fuel in the form of candles. A gaseous material Z which occurs along with petroleum is increasingly being used as a fuel in running vehicles in its compressed form.(a) What are materials, X, Y and Z ?(b) When materials X, Y and Z are burned separately :(i) Which material burns by producing a yellow, luminous flame ?(ii) Which material ultimately burns without producing a flame ?(iii) Which material can burn in a gas stove by producing a blue flame ? |
|
Answer» (a) X is coal; Y is wax; Z is natural gas (b)(i) Y (wax) (ii) X (coal) (iii) Z (natural gas) |
|
| 27. |
Explain the following concept:Capital Clause |
Answer»
|
|
| 28. |
Explain the following concept:Registered Office Clause |
Answer»
|
|
| 29. |
What is seven times the number is 36 less than 10 times the number. Find the number. |
|
Answer» Let the number be x then 10x-7x=36 =>3x=36 =>x=36/3=12 Let the number be x Seven times the number = 7x A/Q, 7x = 10x - 36 7x - 10x = -36 -3x = - 36 x = -36/-3 (- on both get cancelled ) x = 12 Number = 12 |
|
| 30. |
What is heredity ? |
| Answer» The transmission of characteristics from generation to another is known as heredity. | |
| 31. |
Where is DNA found in a cell? |
| Answer» DNA is found in the cell nucleus. | |
| 32. |
The chloride of a metal has the formula MCl3 . The formula of its phosphate will be . (a) M2PO4(b) MPO4(c) M3PO4(d) M(PO4)2 |
|
Answer» Correct option is (b) MPO4 |
|
| 33. |
What did they eat in dinner? |
|
Answer» They ate vegetables, kair-sangri, kadai rice, lady finger vegetable, chapatti, salad etc. |
|
| 34. |
Kunti was happy after begetting her first child. |
|
Answer» Kunti with a heavy heart, placed the baby in a basket and set it afloat on the river Ganga. |
|
| 35. |
What did Kunti do with the child? |
|
Answer» Kunti placed the baby in a basket and set it afloat on the river Ganga. |
|
| 36. |
Why was Kunti disturbed? |
|
Answer» The Pandavas would fight against the Kauravas and Karma was on Duryodhana’s side. Karma would fight against his brothers. So Kunti was disturbed. |
|
| 37. |
What was Kunti blessed with? |
|
Answer» Kunti was blessed with a child who would prove to the greatest of all heroes. |
|
| 38. |
Whom did Kunti invoke? |
|
Answer» Kunti invoked Surya, the Sun God. |
|
| 39. |
It was the Pandavas who did not treat Karma kindly. |
|
Answer» When Krupa challenged Karma to reveal his parentage at the tournament, Bhima flung hot words at Karma, and Duryodhana befriended Karma. |
|
| 40. |
What did Krishna tell Kunti? |
|
Answer» “War is near “Krishna said, your sons will fight against their cousins. There will be much bloodshed.” |
|
| 41. |
When did Kunti meet Karma to reveal the truth? |
|
Answer» Kunti met Karma on the banks of the Ganga where he was praying in the mornings. |
|
| 42. |
अवकल समीकरण की कोटि एवं घात (यदि परिभाषित हो) ज्ञात कीजिएy” + (y’)2 + 2y = 0 |
|
Answer» चूँकि दिए गए अवकल समीकरण में उच्चतम कोटि का अवकलज y” है जिसकी कोटि 2 तथा घात 1 है। अत: अवकल समीकरण की कोटि 2 तथा घात 1 है। |
|
| 43. |
अवकल समीकरण की कोटि एवं घात (यदि परिभाषित हो) ज्ञात कीजिएy” + 2y’ + siny = 0 |
|
Answer» चूँकि दिए गए अवकल समीकरण में उच्चतम कोटि का अवकलज y” है तथा यह y’, y” में बहुपदी है। अत: अवकल समीकरण की कोटि 2 तथा घात 1 है। |
|
| 44. |
सिद्ध कीजिए कि किसी समतल में स्थित बिन्दुओं के समुच्चय में R : { ( P, Q : बिन्दु P की मूलबिन्दु से दूरी, बिन्दु Qकी मूलबिन्दु से दूरी के समान है} द्वारा प्रदत्त सम्बन्ध R एक तुल्यता सम्बन्ध है। पुनः सिद्ध कीजिए कि बिन्दु P ≠ (0, 0) से सम्बन्धित सभी बिन्दुओं का समुच्चय P से होकर जाने वाले एक ऐसे वृत्त को निरूपित करता है, जिसका केन्द्र मूलबिन्दु पर है। |
|
Answer» दिया है, A समतल में बिन्दुओं को समुच्चय है। तथा R = { ( P, Q) : मूलबिन्दु से P तथा Q की दूरी समान है } = { (P, Q) : OP = OQ} 1. R स्वतुल्य है, क्योंकि OP अपने ही बराबर है। 2. R सममित है, यक्योंकि OP = OQ ⇒ OQ = OP 3. R संक्रामक है, क्योंकि OP = OQ, OQ = QR ⇒ OP =QR 1, 2 तथा 3 से स्पष्ट है कि R स्वतुल्य, सममित तथा संक्रामक है। अत: R तुल्यता सम्बन्ध है। चूँकि o मूलबिन्दु है तथा P वृत्त की परिधि पर रहता है अर्थात् यदि OP = K ⇒ बिन्दु P एक वृत्त पर रहता है जो 0 से K दूरी पर है। अतः बिन्दु P ≠ (0, 0) से सम्बन्धित सभी बिन्दुओं का समुच्चय P से होकर जाने वाले एक ऐसे वृत्त को निरूपित करता है, जिसका केन्द्र मूलबिन्दु पर है। |
|
| 45. |
प्रश्न में सत्यापित कीजिए कि दिया हुआ फलन (स्पष्ट अथवा अस्पष्ट) संगत अवकल समीकरण का हल हैy = x2 + 2x + C : y’ – 2x – 2 = 0 |
|
Answer» दिया है, y = x2 + 2x + C x के सापेक्ष अवकलन करने पर , y’ = 2x + 2 + 0 ⇒ y’ – 2x – 2 = 0 ∴ y = x2 + 2x + C, अवकल समीकरण y’ – 2x – 2 = 0 का हल है। |
|
| 46. |
प्रश्न में सत्यापित कीजिए कि दिया हुआ फलन (स्पष्ट अथवा अस्पष्ट) संगत अवकल समीकरण का हल हैy = cos x + C : y’ + sin x = 0 |
|
Answer» दिया है, y = cos x + C x के सापेक्ष अवकलन करने पर, y’ = – sin x + 0 या y’ + sin x = 0 ∴ y = cos x + C, अवकल समीकरण y’ + sin x = 0 का हल है। |
|
| 47. |
अवकल समीकरण की कोटि एवं घात (यदि परिभाषित हो) ज्ञात कीजिएd4y/dx4 + (sinyIII) = 0 |
|
Answer» दी गई अवकल समीकरण अवकलजों में बहुपद समीकरण नहीं है। ∴ इसकी घात परिभाषित नहीं है। जबकि कोटि = 4 |
|
| 48. |
सिद्ध कीजिए कि R में R = { (a, b) : a ≤ b}, द्वारा परिभाषित सम्बन्ध R स्वतुल्य तथा संक्रामक है किन्तु सममित नहीं है। |
|
Answer» माना R कोई वास्तविक संख्याओं का समुच्चय है तथा R = { (a, b) : a ≤ b} 1. R स्वतुल्य है, क्योंकि a ≤ a ⇒ a = a 2. R सममित नहीं है, क्योंकि a, b से कम है तब b, a से कम नहीं है। यदि 1, 2 से कम है तब 2, 1 से कम नहीं हो सकती। 3. R संक्रामक है, क्योंकि a ≤ b और b ≤ c तब a ≤ b अत: 1, 2 व 3 से स्पष्ट है कि R स्वतुल्य और संक्रामक है परन्तु सममित नहीं है। |
|
| 49. |
सिद्ध कीजिए कि किसी कॉलेज के पुस्तकालय की समस्त पुस्तकों के समुच्चय A में R = { (x, y) : x तथा y में पेजों की संख्या समान है} द्वारा प्रदत्त सम्बन्ध R एक तुल्यता सम्बन्ध |
|
Answer» दिया है, A किसी कॉलेज के पुस्तकालय की समस्त पुस्तकों का समुच्चय है। तथा R = { (x, y) : x तथा y में पेजों की संख्या समान है } 1. R स्वतुल्य है, क्योंकि बराबर पृष्ठों वाली प्रत्येक पुस्तक में पृष्ठों की संख्या बराबर होगी। 2. R सममित है, क्योंकि x, y पुस्तकों में पृष्ठ बराबर है तो y, x पुस्तकों में भी पृष्ठ बराबर होगे। 3. R संक्रामक है, क्योंकि x, y तथा y, z पुस्तकों में पृष्ठ बराबर हैं तो x, z पुस्तकों में भी पृष्ठ बराबर होंगे। अत: 1, 2 व 3 से स्पष्ट है कि R स्वतुल्य, सममित तथा संक्रामक है। इसलिए R तुल्यता सम्बन्ध है। |
|
| 50. |
सिद्ध कीजिए कि f(x) = [x] द्वारा प्रदत्त महत्तम पूर्णाक फलन f : R – R, न तो एकैकी है और न आच्छादक है, जहाँ [x], x से कम या उसके बराबर महत्तम पूर्णांक को निरूपित करता है। |
|
Answer» स्पष्ट है कि f(x) का प्रान्त = R तथा f(x) = 0 Y x e[0, 1) ∴ f : R → R एकैकी नहीं है। पुनः f(x) केवल पूर्णांक मान ग्रहण करता है। ∴ सह प्रान्त के अपूर्णांक अवयव प्रान्त के किसी भी अवयव के प्रतिबिम्ब नहीं हैं। ∴ f : R → R आच्छादक नहीं है। अत: f : R → R न तो एकैकी है और न ही आच्छादक। |
|