Explore topic-wise InterviewSolutions in Current Affairs.

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.

The temperature and carbon content at which eutectic reaction occurs in Fe-C equilibrium diagram are A. 723°C and 0.02%C B. 723°C and 0.80%C C. 910°C and 4.3%C D. 1130° C and 4.3%C

Answer»

C. 910°C and 4.3%C 

2.

Eutectoid product in Fe-C system is called A. Pearlite B. Bainite C. Ledeburite D. Spheroidite

Answer»

Eutectoid product in Fe-C system is called Pearlite.

3.

 Hypereutectoid steels have structure of A. Pearlite alone B. Phases of ferrite and pearlite C. Phases of cementite and pearlite D. Phases of cementite and pearlite

Answer»

C. Phases of cementite and pearlite

4.

The percent of total iron in body in hemoglobin is (A) 10–20 (B) 20–30 (C) 30–40 (D) 60–70

Answer»

The percent of total iron in body in hemoglobin is  60–70.

5.

All food should be covered true or falseans:true

Answer»
True, because the bacteria attack as soon as any food item is kept exposed. Also, because there is risk of flies flying over it and making it unfit for consumption.
6.

4. The hair follicles produce oil which keep the hair smooth.  ans:oil

Answer»

The hair follicles produce oil which keeps the hair smooth.

7.

Now fill in the blanks with ‘in’, ‘on’ and ‘at’. 1. Sarathchandra and Keerthana are brother and sister. Sarathchandra was born —(1)— 25th April —(2)— 2000. Keerthana was born —(3)— December 2, 2001. They are with their parents. They Live —(4)— Kondamudusupalem, a small village —(5)— Prakasam District. They play games —(6)— school. It is usually very hot —(7)— May —(8)— their village. So they spend their summer —(9)— Hyderabad —(10)— their uncle’s house. Mr. Srisailam is their uncle. He resides —(11)— High Court Colony —(12)— Hyderabad with his wife, Jagadeeswan and his daughter, Vishnu Priya. 2. Sridevi was a famous Indian actress. She was born ——– 13 August 1963 ——– Sivakasi. Her parents were Ayyappan and Rajeswari. She acted ——– 285 films. 3. Raman was born ——– November 7, 1888 and did his M.A. Course ——– Presidency College ——– Madras.

Answer»

1. 1) on 

2) in 

3) on 

4) at 

5) in 

6) at 

7) in 

8) at 

9) in 

10) at 

11) at 

12) in 

2. on, at, in 

3. on, at, in

8.

________ I read, the more I understand. A) The more B) So much C) How much D) For how much

Answer»

Correct option is A) The more

9.

The rest period for hair follicles is called as 1. Telogen 2. Anagen 3. Catagen

Answer»

Correct option: 1.Telogen

10.

Fill in the blanks withtoo, throughout; however ; meanwhile ; against ; later. 1) The house was painted white .......... 2) They are fighting ......... terrorism. 3) Bob spent an hour with his computer, Ann ....... took care of the children of her own. 4) He wanted to take no risks ........ small. 5) See you .......... 6) When I’ve finished painting the hall, I’m going to do the kitchen ..........

Answer»

1) throughout 

2) against 

3) meanwhile 

4) however

5) later 

6) too

11.

________ he does his work, I don’t mind what time he arrives at the office. A) So far as B) So long as C) In case D) Meanwhile

Answer»

Correct option is B) So long as

12.

Distinguish between(a) Simple epithelium and compound epithelium.(b) Cardiac muscle and striated muscle(c) Dense regular and dense irregular connective tissues(d) Adipose and blood tissue(e) Simple gland and compound gland

Answer»

(a)

Simple epitheliumCompound epithelium
1. It is composed of only one layer of cells.
2. It is mainly involved in the function of absorption and secretion.
3. It is present in the lining of the stomach, intestine.
1. It is composed of many layers of cells.
2. It is mainly involved in the function of protection and has a limited role in absorption and secretion.
3. It is present in the lining of the pharynx and buccal cavity.

(b)

Cardiac musclesStriated muscles
1. They are involuntary in function.
2. They are multi-nucleate and branched.
3. They are found only in the heart.
1. They are voluntary in function.
2. They are multi-nucleate and unbranched.
3. They are found only in triceps, biceps, and limbs.

(c)


Dense regular connective tissuesDense irregular connective tissues
1. In dense regular connective tissues, collagen fibres are present in rows between parallel boundless fibres.
2. They are present in tendons and ligaments.
1. In dense irregular connective tissues, fibres are arranged irregularly.
 2. They are present in the skin.

(d)

Adipose tissueBlood tissue
1. It is composed of collagen fibres, elastin fibres, fibroblasts, macrophages, and adipociytes.
 2. It helps in the synthesis, storage, and metabolism of fats.
 3. It is present beneath the skin.
1. It is composed of RBCs, WBCs, platelets, and plasma.
2. It helps in the transportation of food, wastes, gases, and hormones.
3. It is present in the blood vessels.

(e)

Simple glandsCompound glands
1. They contain isolated glandular cells. 2. They are unicellular. 3. Examples include goblet cells of the alimentary canal.1. They contain a cluster of secretory cells. 2. They are multicellular. 3. Examples include salivary glands.

13.

Answer in one word or one line.(i) Give the common name of Periplaneta americana.(ii) How many spermathecae are found in earthworm?(iii) What is the position of ovaries in the cockroach?(iv) How many segments are present in the abdomen of cockroach?(v) Where do you find malphigian tubules?

Answer»

(i) The common name of Periplaneta americana is the American cockroach.
(ii) Four pairs of spermathecae are present in earthworms. They are located between sixth and the ninth segments. They help in receiving and storing the spermatozoa during copulation.
(iii) In a cockroach, the pair of ovaries is located between 12th and 13th abdominal segments.
(iv) In both sexes, the abdomen of a cockroach consists of ten segments.
(v) Malphigian tubules are main excretory organs of cockroaches. They form a part of the alimentary canal.

14.

Mark the odd one in each series:(a) Areolar tissue; blood; neuron; tendon(b) RBC; WBC; platelets; cartilage(c) Exocrine; endocrine; salivary gland; ligament(d) Maxilla; mandible; labrum; antennae(e) Protonema; mesothorax; metathorax; coxa

Answer»

(a) Areolar tissue, blood, and tendons are examples of connective tissues. Neuron is an example of neural tissue.
(b) RBCs, WBCs, and platelets are the three most important components of blood. Cartilage is therefore, the odd one out.
(c) Exocrine, endocrine, and salivary glands are examples of simple glandular epithelium. Ligament is a connective tissue.
(d) Maxilla, mandible, and labrum are mouthparts of a cockroach. Antennae, on the other hand, are present in the head region of cockroaches.
(e) Protonema forms the developmental stage in the life cycle of a moss. Mesothorax, metathorax, and coxa are parts or segments present in the legs of a cockroach.

15.

Answer the following: (i) What is the function of nephridia? (ii) How many types of nephridia are found in earthworm based on their location?

Answer»

(i) Nephridia are segmentally arranged excretory organs present in earthworms.
(ii) On the basis of their location, three types of nephridia are found in earthworms. They are:

  • Septal nephridia: These are present on both sides of the inter-segmental septa behind the 15th segment. They open into the intestines.
  • Integumentary nephridia: These lie attached to the body wall from the third segment to the last segment, which opens on the body surface.
  • Pharyngeal nephridia: These are present as three paired tufts in fourth, fifth, and sixth segments.
16.

Column IColumn II(a) Compound epithelium(b) Compound eye(c) Septal nephridia(d) Open circulatory system(e) Typhlosole(f) Osteocytes(g) Genitalia(i) Alimentry canal(ii) Cockroach(iii) Skin(iv) Mosaic vision(v) Earthworm(vi) Phallomere(vii) Bone

Answer»
Column IColumn II
(a) Compound epithelium
(b) Compound eye
(c) Septal nephridia
(d) Open circulatory system
(e) Typhlosole
(f) Osteocytes (g) Genitalia
(iii) Skin
(iv) Mosaic vision
(v) Earthworm
(ii) Cockroach
(i) Alimentary canal
(vii) Bone
(vi) Phallomere

17.

Mention briefly about the circulatory system of earthworm

Answer»

Earthworms (Pheretima) have closed blood vascular systems, which consists of the heart, blood vessels, and capillaries. The heart pumps blood for circulating it in one direction. Blood is supplied by smaller blood cells to the gut nerve cord and the body wall. Blood glands are present in the 4th, 5th, and 6th segments, which produce blood cells and haemoglobin dissolved in blood plasma. Blood cells in earthworms are phagocytic in nature.

The circulatory system of the earthworm is closed type as the blood flows in fine closed blood vessels. It includes blood, blood vessels, heart and anterior loops and blood glands. 

1. Blood-  A coloured respiratory pigment haemoglobin is found to be present in the plasma. Due to this, the colour of the plasma is red. In the blood, only one type of blood corpuscles, the leucocytes are present in the blood of the earthworm. 

2. Blood vessels- the blood vessels found in earthworm are as follows: 

Dorsal blood vessel- These extend from one end of the body to the other. The blood flows in this vessel from behind to forward on the dorsal side of the alimentary canal. The dorsal blood vessel has valves which prevent the backward flow of blood. 

Ventral blood vessel- These extend from the one end to the other end of the body. It does not have any valves and flow of the blood is from the anterior to the posterior end of the body. It is the major distributing vessel. 

Sub-neural blood vessel- It runs from the posterior end of the body up to the 14th segment in front. It collects blood from the body wall and nerve cord. This blood is then sent to the dorsal blood vessel through commissural vessels. 

Lateral oesophageal vessel- These are the paired blood vessels lying one on either ventrolateral side of the alimentary canal between the body wall and the alimentary canal in the first 14th segment. 

Supra-oesophageal blood vessel- It is a single vessel which lies on the dorsal side of the alimentary canal between the 9th and 13th segment. It receives blood from the lateral oesophageal through two pairs of anterior loops and pours into two pairs of latero-oesophageal hearts present in the 12th and 13th segments. 

Hearts and anterior loops- In earthworm, four pairs of tubular hearts which are provided with valves. The anterior two pairs of the heart are known as the lateral heart and they lie in the 7th and 9th segment. They receive blood from the dorsal blood vessel and convey it to the ventral blood vessel. The posterior two pairs of hearts are situated in the 12th and 13th segments. These carry blood from the dorsal blood vessel and supra oesophageal vessel to ventral blood vessel. Two pairs of anterior loops are present in 10th and 11th segments.

18.

In blood the values of manganese in µg/100 ml varies between (A) 0–4 (B) 2–4 (C) 3–5 (D) 4–20

Answer»

Correct option (D) 4–20

19.

Do all food contain all the required nutrients

Answer»

Most food items, usually, have more than one nutrient. You may have noticed this while recording your observations in Table 2.2. However, in a given raw material, one particular nutrient may be present in much larger quantity than in others. For example, rice has more carbohydrates than other nutrients.

20.

What is a parasite

Answer»

A plant or an animal organism that lives in or on another and takes its nourishment from that other organism. Parasitic diseases include infections that are due to protozoa, helminths, or arthropods. For example, malaria is caused by Plasmodium, a parasitic protozoa.

21.

Total zinc content of human body is about (A) 800 mg (B) 1200 mg (C) 2000 mg (D) 3200 mg

Answer»

Correct option (C) 2000 mg

22.

What would you say to a grumbling group mate who is finding fault with everything around? A) Better late than never. B) East or West, home is best. C) To get out of bed on the wrong side. D) Promise little, but do much. E) Make hay while the sun shines.

Answer»

Correct option is C) To get out of bed on the wrong side.

23.

Read the following extract carefully and answer the questions that follow: Irrigating trees and fields This is an excerpt from the Babumana that describes the irigation devices the emperor observed in Northern India : The greater part of Hindustan country is situated ont leyel land. Many though its towns and cultivated lands are, it nowhere has running waters. For water is not at all a necessity in cultivating crops and orchards. Autumn crops grow by the downpour of the rains themselves, and strange it is that spring crops grow even when no rains fall. (However) to young trees water is made to flow by means of buckets or wheels.... In Lahore, Dipalpur (both in present-day Pakistan) and those other parts, people water by means of a wheel. They make two circles of rope long enough to suit the depths of the well, fix strips of wood between them, and on these fasten pitchers. The ropes with the wood and attached pitchers are put over the wheel-well. At one end of the wheel-axle a second wheel is fixed, and close to it another on an upright axle. The last wheel the bullock turns, its teeth catch in the teeth of the second (wheel), and thus the whel with the pitchers is turned. A trough is set where the water empties from the pitchers and from this the water is conveyed everywhere In Agra, Chandwar, Bayana (all in present-day Utar Peadesh) and those pacus agaia,-people water with a bucket. At the well-edge they sct up a fork of wood, having a roller adjusted between the forks, tie a rope to a large bucket, put the Iope over a roller, and tie its other end to the bullock One person most drive the balioclk another empty the bucket. Explain any three factors which are responsible for the expansion of agriculture in India.

Answer» Factors which are responsible for the expansion of agriculture in India:
(i) Its level land which can be cultivated without running watet.
(ii) Autumn crops can grow by the down pour of the rains fixed. And close
(iii) Spring crops grow even when no rains fall
(iv) Better irrigation technology
(v) The abundance of land.
(vi) Availability of labour.
(vii) Mobility of peasants.
24.

Read the following extract carefully and answer the questions that follow: Irrigating trees and fields This is an excerpt from the Babumana that describes the irigation devices the emperor observed in Northern India : The greater part of Hindustan country is situated ont leyel land. Many though its towns and cultivated lands are, it nowhere has running waters. For water is not at all a necessity in cultivating crops and orchards. Autumn crops grow by the downpour of the rains themselves, and strange it is that spring crops grow even when no rains fall. (However) to young trees water is made to flow by means of buckets or wheels.... In Lahore, Dipalpur (both in present-day Pakistan) and those other parts, people water by means of a wheel. They make two circles of rope long enough to suit the depths of the well, fix strips of wood between them, and on these fasten pitchers. The ropes with the wood and attached pitchers are put over the wheel-well. At one end of the wheel-axle a second wheel is fixed, and close to it another on an upright axle. The last wheel the bullock turns, its teeth catch in the teeth of the second (wheel), and thus the whel with the pitchers is turned. A trough is set where the water empties from the pitchers and from this the water is conveyed everywhere In Agra, Chandwar, Bayana (all in present-day Utar Peadesh) and those pacus agaia,-people water with a bucket. At the well-edge they sct up a fork of wood, having a roller adjusted between the forks, tie a rope to a large bucket, put the Iope over a roller, and tie its other end to the bullock One person most drive the balioclk another empty the bucket. What was the necessity of irrrigation ?

Answer» Most of Hindustan country is situated on level land. This had many towns and cultivated lands, but nowhere has running water. Water was required to water young trees.
25.

Read the following extract carefully and answer the questions that follow: Irrigating trees and fields This is an excerpt from the Babumana that describes the irigation devices the emperor observed in Northern India : The greater part of Hindustan country is situated ont leyel land. Many though its towns and cultivated lands are, it nowhere has running waters. For water is not at all a necessity in cultivating crops and orchards. Autumn crops grow by the downpour of the rains themselves, and strange it is that spring crops grow even when no rains fall. (However) to young trees water is made to flow by means of buckets or wheels.... In Lahore, Dipalpur (both in present-day Pakistan) and those other parts, people water by means of a wheel. They make two circles of rope long enough to suit the depths of the well, fix strips of wood between them, and on these fasten pitchers. The ropes with the wood and attached pitchers are put over the wheel-well. At one end of the wheel-axle a second wheel is fixed, and close to it another on an upright axle. The last wheel the bullock turns, its teeth catch in the teeth of the second (wheel), and thus the whel with the pitchers is turned. A trough is set where the water empties from the pitchers and from this the water is conveyed everywhere In Agra, Chandwar, Bayana (all in present-day Utar Peadesh) and those pacus agaia,-people water with a bucket. At the well-edge they sct up a fork of wood, having a roller adjusted between the forks, tie a rope to a large bucket, put the Iope over a roller, and tie its other end to the bullock One person most drive the balioclk another empty the bucket. Explain the irrigation technology as observed by the Emperor.

Answer» The Emperor observed that technology used for irrigation was that people water by means of a wheel. They make two circles of rope to suit the depth of the well, fix strips of wood berween them, and on this fasten pitchers (Earthen pot, Ghara). Such ropes are put over the wheel-well. At one cnd of the wheel axle, a second wheel to it another on an upright axle. The last wheel the bullock turns and thus the wheel with pitchers is curned. A trough is set where the water empties from the pitchers and from this water is conveyed everywhere.
26.

The trace element catalyzing hemoglobin synthesis is (A) Manganese (B) Magnesium (C) Copper (D) Selenium

Answer»

Correct option (C) Copper

27.

This plasma cell secretes:A.      Antibody of a single specificity related to that on the surface of the parent B-cellB.      Antibody of two antigen specificitiesC.      The antigen it recognizesD.      Many different types of antibodyE.       Lysozyme

Answer»

Answer: Antibody of a single specificity related to that on the surface of the parent B-cell 

B cell differentiate into plasma cells that produce antibodies.
Plasma cells produce a single kind of antibody in a single class of immunoglobulin. In other words, every B cell is specific to a single antigen.

28.

Class 12

Answer»

Nitrogen's maximum covalency is indeed 4.

Nitrogen has two 2s and three 2p valence electrons. By sharing the three 2p electrons, nitrogen can form three covalent bonds. For example, NH3. But still the nitrogen atom has a lone pair of electrons from 2s orbital. By donating these two electrons from lone pair, it can form one bond. For example, NH4+.
Thus, nitrogen can form four bonds

29.

Give the generalizations concerning the composition of equilibrium mixtures.

Answer»

(i) If Kc > 103, products predominates over reactants i.e; if Kc is very large, the reaction proceeds nearly to completion. 

(ii) If Kc < 10-3, reactants predominates over products i.e; if Kc is very small, the reaction proceeds rarely. 

(iii) If Kc is in the range of 10-3 to 103, appreciable concentration of both reactants and products are present.

30.

Which of the following opioid analgesics is used in combination with droperidol in neuroleptanalgesia? a) Morphine b) Buprenorphine c) Fentanyl d) Morphine 

Answer»

(c)  Fentanyl

31.

Tick narcotic analgesic, which is a phenylpiperidine derivative: a) Codeine b) Dezocine c) Fentanyl d) Buprenorphine 

Answer»

(c)  Fentanyl

32.

Indicate the opioid analgesic, which has 80 times analgesic potency and respiratory depressant properties of morphine, and is more effective than morphine in maintaining hemodynamic stability? a) Fentanyl b) Pentazocine c) Meperidine d) Nalmefene

Answer»

(a)  Fentanyl 

33.

Indicate the opioid analgesic, which is used for relieving the acute, severe pain of renal colic: a) Morphine b) Naloxone c) Methadone d) Meperidine

Answer»

d)  Meperidine

34.

If--reproduction is a defining peoperty then, what about sterile organisms

Answer»

Hi Hari,

As we know that some organisms are living inspite of that they can not reproduce. So,Growth and Reproduction cannot be taken as the defining property of all living beings because there are certain living beings in the world which do not show these properties and yet they are living beings. For ex: Drones, Infertile couples cannot reproduce yet they are living, . Similarly some non-living also grow in size but they are not living. That's why it is not taken as defining property.

35.

A) Echinodermata: Pentamerous radial symmetry & mostly internal fertilizationB) Mollusca: Normally oviparous & development through a trochophore or veligerC) Arthropoda: Body divided into head, thorax & abdomen & respiration by tracheaeD) Chordata: Notochord at some stage & separate anal & urinal openings to outside.

Answer»

Correct answer:
(c) Arthropoda-Body divided into head, thorax and abdomen and respiration by tracheae

Arthropoda is the largest phylum of animal kingdom. Body of arthropod is divisible into head,thorax and abdomen. Head and thorax often fused to form cephalothorax. The respiration takes place by general body surface,gills,tracheae or book lungs. Mollusks are dioecious or monoecious,one or more gonads with gonoducts,opening into renal ducts or to exterior. The fertilization is external or internal,development direct or through free larval forms. Echinoderms have a pentamerous radial symmetry derived from an original bilateral symmetry. The fertilization is external,development indirect through free-swimming larval forms. Chordates are sharphy distinguished from non-chordates by presence of notochord,dorsal tubular central nervous system and pharyngeal gills slits.

36.

What is haploidy? How are haploid plants raised? How are they helpful in plant breeding ?

Answer»

A haploid is a cell or organism that has a single set of chromosomes that are not paired. The haploid gamete is normally produced during plant cell division. During fertilization, these cells normally merge with other similar haploid cells. A haploid cell only has half the number of chromosomes as are present in diploids.

A method is presented by which hundreds of haploid plants of various species of Nicotiana can be raised from pollen grains. Stamens should be excised when pollen grains have been individualized, but are still uninucleate and free of starch. When grown in vitro on a relatively simple medium, some pollen grains proliferate into embryo-liké, structures which develop in stages similar to those of zygotic embryos. The plantlets mature and flower profusely, but do not set seed.

Plant breeding is the purposeful manipulation of plant species in order to create desired genotypes and phenotypes for specific purposes. 

This manipulation involves either controlled pollination, genetic engineering, or both, followed by artificial selection of progeny. Plant breeding often, but not always, leads to plant domestication. 

Plant breeding has been practiced for thousands of years, since near the beginning of human civilization. It is now practiced worldwide by government institutions and commercial enterprises. International development agencies believe that breeding new crops is important for ensuring food security and developing practices through the development of crops suitable for their environment.

37.

A) SpeciesB) KingdomC) FamilyD) Variety

Answer»

Yes it will be Species

38.

a) Interaction with the environment & progressive evolutionb) Reproductionc) Growth & Movementd) Responsiveness to touch

Answer»

Answer is (b) Reproduction

Only living organisms have the ability to reproduce(produce organisms of their own kind). Even though all other options are seen in living organisms, reproduction is the most fundamental thing. Living organisms do evolve and interact with environment but it is only because reproduction is taking place in every organisms.

39.

Read the following statements:(A) Growth hormones are also secreted by other non enodocrine tissuepls give the ans only if u r 100% sure

Answer»

The correct option is D is true, B and A is false

  • ANF is atrial natriuretic factor that causes vasodilation and leads to a decrease in blood pressure. 
  • The increase in the blood flow to the atria of the heart causes the release of ANF.
  • It is mainly released by the atria of the heart in response to high blood volume
40.

Which of the following opioid analgesics can produce dysphoria, anxiety and hallucinations? a) Morphine b) Fentanyl c) Pentazocine d) Methadone

Answer»

c) Pentazocine

41.

Which of the following opioid agents is used in the treatment of acute opioid overdose? a) Pentazocine b) Methadone c) Naloxone d) Remifentanyl 

Answer»

Naloxone opioid agents is used in the treatment of acute opioid overdose.

42.

Which of the following opioid analgesics is used in the treatment of acute pulmonary edema? a) Morphine b) Codeine c) Fentanyl d) Loperamide

Answer»

Morphine opioid analgesics is used in the treatment of acute pulmonary edema.

43.

Therapeutic doses of the opioid analgesics: a) Decrease body temperature b) Increase body temperature c) Decrease body heat loss d) Do not affect body temperature 

Answer»

a) Decrease body temperature

44.

Which of the following analgesics is a phenanthrene derivative? a) Fentanyl b) Morphine c) Methadone d) Pentazocine

Answer»

(b)  Morphine

45.

Indicate the neurons, which are located in the locus ceruleus or the lateral tegmental area of the reticular formation: a) Dopaminergic b) Serotoninergic c) Nonadrenergic d) Gabaergic

Answer»

c) Nonadrenergic 

46.

The majority of pteridophytes are homosporous ie. they produce similar kind of spores. Give one example of a heterosporous pteridophyte.

Answer»

Example of a heterosporous pteridophyte Selaginella.

47.

System is shown in the figure and man is pulling the rope from both sides with constant speed `u` find the speed of the block.A. `(3u)/(4)`B. `(3u)/(2)`C. `(u)/(4)`D. none of these

Answer» Correct Answer - A
`u=(0+v_(1))/(2),(v_(1)+v_(2))/(2)=v,(-v_(2)+u)/(2)=v`
Hence `v=` velocity of `M=(3u)/(4)`.
48.

Which of the following statement is // are trueA. work done by kinetic friction on a rigid body may be positiveB. a uniform sphere rolls up an inclined plane without sliding. The friction force on it will be up the incline. (only contact force and gravitational force is acting)C. a uniform sphere rolls down an inclined plane without sliding. The fricition force on it will be up the incline. (only contact force and gravitational force is acting)D. a uniform sphere is left from rest from the top of rough inclined plane. It moves down the plane with slipping. The friction force on it will be up the incline.

Answer» Correct Answer - A::B::C::D
`w=intf_(k)dvec(s) gt0
If `f_(k)` and ds looth are parallel to each other friction force acts up to the inclined to produce angular acceleration.
49.

Consider atoms `H, He^(+), Li^(++)` in their ground states. Suppose `E_(1), E_(2)` and `E_(3)` are minimum energies required so that the atoms `H He^(+), Li^(++)` can achieve their first excited states respectively, thenA. `E_(1)=E_(2)=E_(3)`B. `E_(1) gt E_(2) gt E_(3)`C. `E_(1) lt E_(2) lt E_(3)`D. `E_(1) = E_(2) E_(3)`

Answer» Correct Answer - C
`Delta E prop Z^(2)`
i.e. greatest for `Li^(++)` and minimum for H.
50.

A small sized mass `m` is attached by a massless string (of length `L`) to the top of a fixed frictionless solid cone whose axis is vertical. The half angle at the vertex of cone is theta. If the mass `m` moves around in a horizontal circle at speed `v` , what is the maximum value of `v` for which mass stay in contact with the comes? (g is acceleration due to gravity.) A. `sqrt(gL cos theta)`B. `sqrt(gL sin theta)`C. `sqrt(gL sin theta tan theta)`D. `sqrt(gL tan theta)`

Answer» Correct Answer - C
At maximum velocity the mass will just loose contact with cone and will behave like free conical pendulum with time period :
`T = 2 pi sqrt((L cos theta)/(g))rArr omega =(2pi)/(T)sqrt((g)/(L cos theta))`
Hence `v_(max) = (L sin theta) omega = sqrt(gL sin theta tan theta)`.