Identify the biome that is not correctly matched with the physical parameters given in corresponding Column II and Column III:
Biome | Mean annual temperature | Mean annual precipitation [cm] | |
1. | Tropical forest | 20-25 | 130 - 430 |
2. | Arctic and alpine tundra | -12 - 2 | 10 -125 |
3. | Coniferous forest | -5 - 5 | 100 -200 |
4. | Temperate forest | 8-22 | 50 - 225 |
The most ecologically relevant environmental factor is:
1. Temperature
2. Water
3. Light
4. Soil
If global warming continues, how would the distributional range of some species be affected?
1. There will be a poleward shift
2. There will be an equatorial shift
3. No change expected for any species
4. Shift to marine water from land
Many freshwater animals cannot live for long in sea water and vice versa because of:
1. Buoyancy related problems
2. Lack of impermeable skins
3. Thermolabile enzymes
4. Osmotic considerations
Big holes in Swiss cheese are made by a:
1. | a machine |
2. | a bacterium that produces methane gas |
3. | a bacterium producing a large amount of carbon dioxide |
4. | a fungus that releases a lot of gases during its metabolic activities. |
Which of the following algae is likely to be found in the deepest waters?
(1) Green
(2) Brown
(3) Red
(4) All are found at equal depths
When exposed to cold temperatures, which of the following is responsible for maintaining constant body temperature in humans?
1. Vasoconstriction and shivering
2. Vasodilation and shivering
3. Vasodilation and sweating
4. Vasoconstriction and sweating
Match the items in column 'A' and Column 'B' and choose correct answer.
Column A |
|
Column B |
|
(i) |
Lady Bird |
(a) |
Menthano bacterium |
(ii) |
Mycorrhiza |
(b) |
Trichoderma |
(iii) |
Biological control |
(c) |
Aphids |
(iv) |
Biogas |
(d) |
Glomus |
The correct answer is:
(1) (i) - b, (ii) - d, (iii) - c, (iv) - a
(2) (i) - c, (ii) - d, (iii) - b, (iv) - a
(3) (i) - d, (ii) - a, (iii) - b, (iv) - c
(4) (i) - c, (ii) - b, (iii) - a, (iv) - d
Under unfavorable conditions, many zooplankton species in lakes and ponds are known to enter a stage of suspended development called as:
1. Dormancy
2. Hibernation
3. Aestivation
4. Diapause
The given age pyramid represents a:
1. Fast expanding population
2. Slowly expanding population
3. Stable population
4. Declining population
Darwinian fitness is represented by:
1. Low r value
2. High r value
3. High K value
4. Low K value
Which one of the following is not a nitrogen-fixing organism?
1. Anabaena
2. Nostoc
3. Azotobacter
4. Pseudomonas
Under a particular set of selection pressures, organisms evolve towards the most efficient:
1. Thermoregulation
2. Water conservation
3. Respiration
4. Reproduction strategy
A population interaction where one species is harmed whereas the other is unaffected is called as:
(1) Mutualism
(2) Competition
(3) Predation
(4) Amensalism
Match the following list of bioactive substances and their roles:
Bioactive substance |
Role |
||
(i) |
Statin |
(a) |
Removal of oil stains |
(ii) |
Cyclosporin |
(b) |
Removal of clots from blood vessels |
(iii) |
Streptokinase |
(c) |
Lowering of blood cholesterol |
(iv) |
Lipase |
(d) |
Immuno-suppressive agent |
Choose the correct match:
1. (i) - b, (ii) - c, (iii) - a, (iv) - d
2. (i) - d, (ii) - b, (iii) - a, (iv) - c
3. (i) - d, (ii) - a, (iii) - d, (iv) - c
4. (i) - c, (ii) - d, (iii) - b, (iv) - a
When certain exotic species are introduced into a geographical area, they become invasive mainly because:
1. The invaded land has unlimited resources for the introduced species
2. The invaded land does not have its natural predator
3. The population of the introduced species in the invaded land is very low
4. Introduced species do not face any competition in the introduced land
In a field experiment, when all Pisaster starfish were removed from an enclosed intertidal area, the result was:
1. Increase in diversity of invertebrates
2. Extinction of many invertebrate species
3. Inability of the Pisaster to enter the area again
4. Replacement of Pisaster by other starfish
The vitamin whose content increases following the conversion of milk into curd by lactic acid bacteria is:
(1) Vitamin C
(2) Vitamin D
(3) Vitamin B12
(4) Vitamin E
Which one of the following alcoholic drinks is produced without distillation?
(1) Wine
(2) Whisky
(3) Rum
(4) Brandy
Match the following list of bacteria and their commercially important products:
|
Bacterium |
|
Product |
(i) |
Aspergullus niger |
(a) |
Lactic acid |
(ii) |
Acetobacter aceti |
(b) |
Butyric acid |
(iii) |
Clostridium Butylicum |
(c) |
Acetic acid |
(iv) |
Lactobacillus |
(d) |
Citric Acid |
Choose the correct match:
(1) (i) - b, (ii) - c, (iii) - d, (iv) - a
(2) (i) - b, (ii) - d, (iii) - c, (iv) - a
(3) (i) - d, (ii) - c, (iii) - b, (iv) - a
(4) (i) - d, (ii) - a, (iii) - c, (iv) - b
As a mechanism of defense against herbivory, Calotropis:
(1) Has large number of thorns
(2) Secretes cardiac glycosides
(3) Produces a neurotoxin, strychnine
(4) Releases a hallucinogen
Which of the following is not an ectoparasite?
1. Lice on humans
2. Copepods on marine fishes
3. Mistletoe on other plants
4. Female Anopheles on humans
The residue left after methane production from cattle dung is:
1. burnt
2. burried in land fills
3. used as manure
4. used in civil construction
To get pollinated by a bee, the Mediterranean Orchid, Ophrys, employs:
1. Sexual deceit
2. Pseudo-copulation
3. Reward in the form of Nectar
4. Place for laying eggs
Which award given to individuals or communities from rural areas that have shown extraordinary courage and dedication in protecting wildlife?
1. Venu Menon Animal Allies Award
2. Amrita Devi Bishnoi Award
3. David Shepherd Wildlife Award
4. The Pledge Award
Slash and burn agriculture leads to nutrient depleted soils and deforestation if:-
1. crash crops are implanted rather than cereals
2. it is practiced in a sufficiently larger area
3. some useful trees are retained by the farmers
4. sufficient time is not allowed to the land to recover
The Montreal Protocol was signed in 1987 to:
1. prevent deforestation around the world
2. control the emission of ozone depleting substances
3. control the green house gases
4. prevent hazards from radioactive nuclear wastes
UV rays are highly injurious to living organisms as:
1. they are a part of invisible electromagnetic spectrum
2. they cannot be stopped by atmospheric gases
3. they are preferentially absorbed by DNA and proteins
4. they cause dissociation of atmospheric oxygen
CFC have a continuing effect on ozone layer as:-
1. the Cl atoms formed by them only act as catalysts in reactions causing degradation of ozone
2. the Cl atoms formed by them are used up in reactions causing degradation of ozone
3. they are being produced in increasing amounts all over the world
4. they are efficiently absorbed by the atmospheric water vapors
The normal greenhouse effect is necessary for survival of life on Earth as it has raised the temperature of Earth’s surface by:-
1. -18° C
2. 15° C
3. 33° C
4. 50° C
The correct descending order of the relative contribution of various greenhouse gases to total global warming is:
1. carbon dioxide; methane; nitrous oxide; CFCs
2. carbon dioxide; CFs; methane; nitrous oxide
3. carbon dioxide; CFs; nitrous oxide; methane
4. carbon dioxide; methane; CFCs; nitrous oxide
The Three Mile island is famous as:
1. it hosted the Kyoto protocol
2. it was the site of a large oil spil
3. it was a site of nuclear accident
4. it hosted the Earth summit
Burying the radioactive wastes is not acceptable to many people as:
1. there is a risk of groundwater contamination
2. it may explode
3. it will harm the buried dead bodies
4. it may get accumulated in vegetations
The "Polyblend" developed by Ahmad Khan is a:
1. possible solution to accumulating plastic wastes
2. method for dealing with electronic wastes
3. synthetic fiber produced in India
4. organic farming product
Ecological sanitation, also known as ecosan, is a new paradigm in sanitation that
1. eliminates the use of conventional pesticides to decrease environmental insult
2. recognizes human excreta and household waste water as resources that can and are recovered, treated, and reused
3. emphasizes the disposal of solid wastes in sanitary landfill sites
4. emphasizes the need for strict legislation against polluting industries
Natural ageing of a lake by biological enrichment of its water is known as:
1. Eutrophication
2. Biomagnification
3. Bioremediation
4. Biofortification
High concentrations of accumulated DDT in birds
1. kills pathogens in their blood
2. causes sterility by affecting gametogenesis
3. leads to premature breaking of eggs
4. causes spasticity of the muscles ofthe body
What was added in 1987 as a pollutant to The Air (Prevention and Control of Pollution) Act, [originally passed in 1981] :
1. radioactive wastes
2. CFCs
3. ground level ozone
4. noise
According to CPCB, what particulate size is most harmful to humans:
1. more than 10 micrometers
2. between 5 to 10 micrometers
3. between 2.5 to 5 micrometers
4. less than 2.5 micrometers
The Earth Summit was held in Rio de Janeiro in:
1. 1987
2. 1990
3. 1992
4. 2002
When a threatened plant needs urgent measures to save it from extinction, the desirable approach is
1. in-situ conservation
2. ex-situ conservation
3. cryopreservation
4. biopreservation
The search for previously unknown compounds in organisms that have never been used in traditional medicine is known as:
1. Biopiracy
2. Bioprospecting
3. Molecular pharming
4 Bioremediation
The most important cause of the loss of biodiversity today is the :
1. Habitat loss and fragmentation
2. Over exploitation
3. Alien species invasion
4. Co-extinctions
Introduction of Lates niloticus led to the extinction of
1. Gambusia
2. Pupfish
3. Cichild fish
4. Chinook salmon
Loss of biodiversity may lead to all except:
1. decline in plant production
2. increased resistance to environmental perturbance
3. increased variability in water use
4. increased variability in pest and disease cycle
Which of the following is not a reason that accounts for greater biodiversity of tropics?
1. availability of more solar energy
2. more niche specialization
3. more time for species diversification
4. large seasonal variations in environmental factors
Although, India has only 2.4 % of world's area, its share of global species diversity is about
1. | 3 % | 2. | 5 % |
3. | 8 % | 4. | 11 % |
The greatest biodiversity on the earth is found in
1. African grasslands
2. Amazonian rain forest in South America
3. Western Ghats in India
4. Nile delta in Egypt
Biodiversity loss is now one of the world's most pressing crises. The primary reason for this is:
1. we cannot do anything about it
2. we are not responsible for this loss
3. we still do not know its entire extent
4. it is affecting only the developing countries
The bark of the yew tree, Taxus brevifolia, is source of:
(1) an antileprosy drug
(2) an anticacer drug
(3) a broad spectrum antibiotic
(4) an analgesic and sedative
The first National Park established in India, the place where project tiger was started in 1972, is in:
(1) Madhya Pradesh
(2) Kerala
(3) West Bengal
(4) Uttarakhand
Mycorrhiza does not help the host plant in:
(1) Enhancing its phosphorus uptake capacity
(2) Increasing its tolerance to drought
(3) Enhancing its resistance to root pathogens
(4) Increasing its resistance to insects.
The most effective device to remove particulate matter from polluted air is:
1. electrostatic precipitator
2. cyclonic separator
3. trajectory separator
4. scrubber
The group most profoundly affected by global warming normally is :-
1. Plants
2. Insects
3. Birds
4. Mammals
The term "detritivore" includes
1. decomposers
2. primary consumers
3. secondary consumers
4. autotrophs
Net primary productivity is the gross primary productivity minus
1. that which is consumed by herbivores
2. that which is consumed by producer in metabolism
3. secondary productivity
4. loss due to mortality
The major reservoir for phosphorous is
(1) Aquifers
(2) Soil and rocks
(3) The atmosphere
(4) Clouds
The accumulation of herbivore biomass in an ecosystem is an example of
1. biogeochemical cycles
2. transpiration
3. net primary productivity
4. secondary productivity
Which of the following pyramids can never be inverted in a natural ecosystem?
1. pyramid of numbers
2. pyramid of energy
3. pyramid of biomass
4. all can be inverted
The earth is an open system with respect to
1. organisms
2. chemicals
3. energy
4. all of the above
BOD of waste water is estimated by measuring the amount of:
(1) total inorganic matter
(2) biodegradable organic matter
(3) oxygen evolution
(4) oxygen consumption.
Plants capture approximately __________________ of the sun's energy while other trophics levels capture about _________________ of the energy available to them in their food.
1. 1%, 10%
2. 10%, 60%
3. 10%, 1%
4. 60%, 10%
Which trophic level is incorrectly defined?
1. Carnivores- secondary or tertiary consumer
2. Decomposer- microbial heterotrophs
3. Herbivores - primary consumer
4. Omnivores - Molds, yeast and mushrooms
Nitrogen gas makes up nearly 80% of Earth's atmosphere, yet nitrogen is often a limiting factor for plant growth. Why ?
1. The atmospheric form of nitrogen cannot be used by plants.
2. Nitrifying bacteria remove usable nitrogen from the soil more repidly than plants can absorb it.
3. Atmospheric nitrogen dissolves readily in the soil but is washed out with every rainfall.
4. Plants must absorb nitrogen through their roots, which are not in contact with the atmosphere.
In general, the biomass in an ecosystem will be greatest at the trophic level comprising.
1. secondary consumers
2. primary consumers
3. producers
4. tertiary consumers
The agriculture practice of breeding and raising livestock is called as:
(1) Domestication
(2) Breeding
(3) Animal husbandry
(4) Bio-fortification
Consider the following two statements:
I. In spite of having more than 70 percent of the world livestock population, the contribution of India and China to the world farm produce is only 25 percent.
II. The productivity per unit of cattle in these countries is very low.
(1) Both I and II are true and II explains I
(2) Both I and II are true but II does not explain I
(3) I is true but II is false
(4) Both the statements are not true
The management of animals for milk and its products for human consumption is called as:-
1. Animal breeding
2. Dairying
3. Domestication
4. Animal husbandry
Which of the following is the most important factor that would lead to increased milk yield in cattle ?
(1) Selection of good breeds
(2) Resistance to diseases
(3) Stringent cleanliness and hygiene
(4) Provision of ideal environmental conditions to cattle
Amongst the following the number of fresh water fishes is:
Catla, Rohu, Common carp, Hilsa, Sardines, Mackerel, Pomfrets
1. 2
2. 3
3. 4
4. 5
A group of animals related by descent and similar in most characters like general appearance, features, size, configuration, etc., are said to belong to a:
(1) Variety
(2) Species
(3) Strain
(4) Breed
The purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant is called:
1. Breeding
2. Genetic farming
3. Phytoremediation
4. r DNA technology
Hisardale is a new breed of:
(1) Sheep developed by crossing Bikaneri ewes and Marino rams.
(2) Sheep developed by crossing Bikaneri rams and Marino ewes.
(3) Goat developed by crossing Bikaneri ewes and Marino rams.
(4) Goat developed by crossing Bikaneri rams and Marino ewes.
Today, all our major food crops are derived from:
1. Wild varieties
2. Domesticated varieties
3. Genetically modified varieties
4. Plant tissue culture
There are several species of honeybees which can be reared. Of these the species reared in India is:
(1) Apis indica
(2) Apis dorsata
(3) Trigona iridipennis
(4) Apis mellifera
Consider the following two statements:
I. An effective germplasm collection is the prerequisite of any successful plant breeding program.
II. Genetic variability is the root of any breeding program.
1. Both I and II are true and II explains I
2. Both I and II are true and II dose not explains I
3. I is true but II is false
4. I is false but II is true
Arrange the following steps of a plant breeding program in a correct chronological manner:
I. Selection and testing of superior recombinants
II. Collection of variability
III. Cross-hybridization among the selected parents
IV. Evaluation and selection of parents
V. Testing, release and commercialization of new cultivars
1. II, IV, I, III, V
2. IV, I, II, III, V
3. II. IV, III, I, V
4. IV, III, II, I, V
Arrange the following alkyl halides in the decreasing order of reactivity
(I)
(II)
(III)
1. I>II>III 2. II>I>III
3. II>III>I 4. III>II>I
Butanenitrile may be prepared by heating-
1. Propyl alcohol with KCN
2. Butyl chloride with KCN
3. Butyl alcohol with KCN
4. Propyl chloride with KCN
Identify (X) in the given sequential reaction.
1. CH3OH
2. Ethyl alcohol
3. Methyl cyanide
4. tert-Butyl alcohol
The correct order of solvolysis in the following alkyl halide is
1. > >
2. > >
3. > >
4. > >
The products of reaction of alcoholic silver nitrite with ethyl bromide are :
1. Ethane
2. Ethene
3. Ethyl alcohol
4. Nitroethane
Order of nucleophilicity in polar protic solvent is
1.
2.
3.
4.
Phenylmagnesium bromide reacts with methanol to give
1. A mixture of toluene and Mg(OH)Br
2. A mixture of phenol and Mg(Me)Br
3. A mixture of anisole and Mg(OH)Br
4. A mixture of benzene and Mg(OMe)Br
can be repared from williamson's synthesis using
1. and C6H5CH2ONa
2. C6H5CH2Cl and
3. and C6H5ONa
4. All of these
The compound which reacts fastest with Lucas reagent at room temperature is:
1. Butan-1-ol
2. Butan-2-ol
3. 2-methylpropan-1-ol
4. 2-methylpropan-2-ol
Phenolphthalein is produced on heating phthalic anhydride and conc. sulphuric acid with
1. Salicylic acid
2. Phenol
3. Phenacetin
4. Phenanthrene
The compound Y in the above sequence of reactions is:
1. 1-Phenylethene
2. 2-Phenyl-2-propanol
3. Acetophenone
4. Benzaldehyde
The most acidic compound among the following is:
1. | o-Cresol | 2. | p-Nitrophenol |
3. | Phenol | 4. | m-Cresol |
Methanol and ethanol can be distinguished by the following:
1. By reaction with metallic sodium
2. By reaction with caustic soda
3. By heating with iodine and washing soda
4. By heating with zinc and inorganic mineral acid
Identify (X) in the sequence :
1. CH3-CH2-CH2OH
2.
3. CH3-O-CH2-CH3
4. CH3-CH2-CHO
The product 'D' in the below mentioned reaction is:
\(CH_3MgBr + \text{cyclopentanone}\ \)
\(\xrightarrow{H_2O}\ A\ \xrightarrow{HBr}\ B\)
\( B\ \xrightarrow{Mg/Ether}\ C \xrightarrow[H_3O^+]{HCHO}\ D\)
1. | 2. | ||
3. | 4. |
Consider the following alcohols,
I. | |
II. | |
III. | |
IV. |
Ease of dehydration of the above alcohols will be in the order of-
1. | I < II < III < IV | 2. | I > II > III > IV |
3. | III < II < I < IV | 4. | II < III < IV < I |
The reaction products of C6H5-O-CH3+ HI
1. C6H5OH + CH3l
2. C6H5l + CH3OH
3. C6H5CH3 +HOI
4. C6H6 + CH3Ol
Debromination of meso-dibromobutane gives mainly
1. n-Butane
2. 1-Butene
3. cis-2-Butene
4. trans-2-Butene
The number of moles of HI
consumed by the given compound is:
1. | 1 | 2. | 2 |
3. | 3 | 4. | 4 |
In the following reaction:
The structure of the major product 'X' is
(1)
(2)
(3)
(4)
The product 'A' is
1.
2.
3.
4.
The compound A can be exclusively oxidized into B by:
1. NaCN, followed by hydrolysis
2. NaOI, followed by H3O+
3. KMnO4(hot), followed by hydrolysis
4. K2Cr2O7, followed by H3O+
X Y
In the above reaction, X and Y are:
1. Identical
2. Homologous
3. Structural Isomers
4. Stereoisomers
Major Product is:
1.
2.
3.
4.
Which compound is most reactive towards nucleophilic addition?
1. CH3CHO
2. PhCOCH3
3. PhCOPh
4. CH3COCH3
The reaction
is fastest when X is
1. Cl
2. NH2
3. OC2H5
4. OCOR
In a set of reaction propionic acid yielded a compound D.
CH3CH2COOH B C
The structure of D would be
1. CH3CH2NHCH3
2. CH3CH2NH2
3. CH3CH2CH2NH2
4. CH3CH2CONH2
R-CH2-CH2OH can be converted into RCH2CH2COOH. The correct sequence of reagents is:
1. PBr3, KCN, H+
2. PBr3, KCN, H2
3. KCN, H+
4. HCN, PBr3, H+
Nitrobenzene on electrolytic reduction in a strongly acidic medium gives
1. Aniline
2. p-aminophenol
3. m-nitroaniline
4. nitrosobenzene
The hydrochlorides of amines form double salt with:
(1) PtCl4
(2) AuCl3
(3) both (a) and (b)
(4) none of these
Among the following non-reducing sugar is :
(1) Glucose
(2) Fructose
(3) Sucrose
(4) Galactose
Glucose when heated with CH3OH in presence of dry HCl, a and b methyl glucoside are formed. This is because it contains
(1) An aldehyde group
(2)-CH2OH group
(3) A ring structure
(4)Five -OH group
Which of the following is step growth polymer?
1. Neoprene
2. Isoprene
3. PAN
4. Nylon-6, 6
Biodegradable polymer among the following is-
1. Polythene
2. Cellulose
3. Nylon-6
4. PVC
Buna-S is a polymer of -
1. Butadiene and Styrene
2. Butene and Styrene
3. Butadiene and Chloroprene
4. Butene and Salicylaldehyde
An example(s) of co-polymer among the following options is :
1. Nylon-6,6
2. Terylene.
3. Buna-S.
4. All of the above.
When glucose is reacted with phenyl hydrazine then osazone is formed. In this reaction how many phenyl hydrazine molecules are used ?
1. 1
2. 2
3. 3
4. 4
The two forms of glucopyranose obtained from solution of D-glucose are called
1. Isomers
2. Anomers
3. Epimers
4. Enantiomers
Glucose and Mannose are
1. C1 epimers
2. Anomers
3. C2 epimers
4. C4 epimers
Three ideal diodes are connected to the battery as shown in the circuit. The current supplied by the battery is:
1. zero
2. \(4~\text{A}\)
3. \(2~\text{A}\)
4. \(6~\text{A}\)
In a common emitter transistor amplifier, the audio signal voltage across resistance of 1 k is 2V. If the base resistance is 200 and the current amplification factor is 50, the input signal voltage will be
(1) 4 mV
(2) 8 mV
(3) 16 mV
(4) 32 mV
If a small amount of aluminium is added to the silicon crystal:
1. | its resistance decreases. |
2. | it becomes a p-type semiconductor. |
3. | there will be fewer free electrons than holes in the semiconductor. |
4. | All of these are correct. |
1.
2.
3.
4.
A transistor is operated in common emitter configuration at When base current is changed from 10mA to 30mA, it produces a change in emitter current from 2A to 4A, the current amplification factor is
1. 100
2. 99
3. 10
4. 9
When a p-n junction is forward biased, then:
1. | the depletion region becomes thick. |
2. | the p-side is at a higher potential than n side. |
3. | the current flowing is zero. |
4. | the effective resistance is of the order of \(10^6 ~\Omega\). |
When a transistor is used as a switch it is in:
1. Active state
2. Cut off state
3. Saturation state
4. Both cut off state and saturation state are possible
Use of transistor as an amplifier works in the region -
1. Cut off region
2. Saturation region
3. Passive region
4. Active region
Which of the following is correct for \(\mathrm{n}\)-type semiconductors?
1. | electron is the majority carriers and trivalent atoms are dopants. |
2. | electrons are majority carriers and pentavalent atoms are dopants. |
3. | holes are majority carriers and pentavalent atoms are dopants. |
4. | holes are majority carriers and trivalent atoms are dopants. |
Which of the following transition in a hydrogen atom will produce radiations of minimum wavelength?
1. n = 2 to n = 1
2. n = 5 to n = 3
3. n = 10 to n = 5
4. n = 10 to n = 3
The ratio of the radius of the nucleus to the radius of an atom is of the order of :
1.
2.
3.
4.
If a radioactive material reduces to 12.5% of its value in 24 days, then its half-life is:
1. 16 days
2. 8 days
3. 4days
4. 2 days
The half-life of a radioactive material depends on
1. The initial amount of material
2. Rate of disintegration
3. Decay constant
4. Temperature and pressure
Binding energy per nucleon is:
1. Maximum for middle-order elements
2. Maximum for lighter order elements
3. Maximum for heavier order elements
4. None of these
1.
2.
3.
4. All of these
For a transistor amplifier, the power gain and voltage gain are 150 and 10 respectively. The current gain is-
1.
2.
3. 15
4. 1500
1.
2.
3.
4.
In semiconductors, which of the following gives the law of mass action?
(where symbols have their usual meanings.)
1. \(n_i=n_e=n_h\)
2. \(n_i^2=n_en_h\)
3. \(n_h>> n_e\)
4. \(n_h<<n_e\)
An amine is reacted with benzene sulphonyl chloride then a solid compound is formed which is insoluble in alkali. The amine is:
1. CH3-CH2-NH2
2. CH3-NH-CH2-CH3
3. (CH3)3N
4. C6H5-NH2
The correct order of basicities of the following compounds is:
(1)
(2)
(3)
(4)
1. 2>1>3>4
2. 1>3>2>4
3. 3>1>2>4
4. 1>2>3>4
1.
2.
3.
4.
Monochromatic radiation emitted when an electron in a hydrogen atom jumps from the first excited state to the ground state irradiates a photosensitive material. The stopping potential is found to be 4V. The threshold wavelength of the material is
A biconvex lens of glass has a radius of curvature 20cm. Which one of the following gives the correct position and nature of the image formed when an object is placed at 40cm from the lens?
1. Real, inverted and same size
2. real, inverted and diminished
3. Real, inverted and enlarged
4. Virtual, upright and enlarged
In a photoelectric experiment using a metal of work function 1.8 eV, if the maximum kinetic energy of emitted electrons is 1.5eV, then the corresponding value to stopping potential is:
1. 1.8V
2. 3.3V
3. 0.3V
4. 1.5V
Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the accelerating voltage is reduced to 6.25 kV, the resolving power of the microscope would:
1. Increase to 4 time
2. Increases to 2 times
3. Decrease to half
4. Decrease to 1/4th
When the light of wavelength is used in a photoelectric experiment, the maximum kinetic energy of emitted electrons is found to be K. What will the maximum kinetic energy of the photoelectrons when the light of wavelength is used instead of :
1. Zero
2. Non zero but less than 2 K
3. 2K
4. More than 2K
1. 2
2. 4
3.
4.
A parallel beam of moving electrons is incident normal on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the slit is further narrowed, then which of the following statements is correct?
1. | The diffraction pattern is not observed on the screen in the case of electrons. |
2. | The angular width of the central maximum of the diffraction pattern will increase. |
3. | The angular width of the central maximum will decrease. |
4. | The angular width of the central maximum will remain the same. |
In Young's double-slit experiment, the slits are 0.4 mm apart and illuminated by photons of two wavelengths = 600 nm and = 700nm. At what minimum distance from the common center, bright fringe from one interference pattern coincides with bright fringe from other? (Given that the distance of the screen from the plane of slits is 80cm.)
1. 7.2 mm
2. 6.0 mm
3. 8.4 mm
4. 9.8 mm
The concept of matter-wave was given by:
1. de-Broglie
2. Einstein
3. Maxwell
4. Bohr
A ray of light will suffer total internal reflection if it-
1. goes from rare medium to denser medium
2. Incident at less than the critical angle
3. Strikes the interface normally
4. incident at an angle greater than critical angles
A converging beam of light is incident on a concave lens of focal length 30cm, in such a way that their point of intersection would lie at a height 1cm above the principal axis and at a distance of 24cm from the position of the lens if there was no lens. Find the nature of the image formed when the beam passes through the lens.
1. Real at a distance 60cm from the lens
2. Real at a distance 120cm from the lens
3. Virtual at a distance 60cm from the lens
4. Virtual at a distance 120 cm from the lens
One face of a prism of apex angle 30 is silvered and a ray of light is incident on the first face at an angle i such that it retraces its entire path after reflection from the silvered face. If the refractive index of prism material is 2, then the value of i must be -
1. 45
2. 60
3. 30
4. 90
The shortest wavelength of Balmer series is about
1. 912
2. 121
3. 3648
4. 4864
When the light of wavelength is made to fall on metal in a photoelectric experiment, the maximum kinetic energy of emitted electrons is found to be 2.5eV. The work function of the metal is:
1. 2.5eV
2. 3.1eV
3. 0.9eV
4. 1.5eV
1.
2.
3.
4.
The angular speed of electron in a hydrogen atom in orbit is proportional to -
1.
2.
3.
4.
The focal length of a convex lens is f. An object is placed at a distance x from the focal point and a real image is formed. The linear magnification has a magnitude
1.
2.
3.
4.
A diffraction pattern is observed using a beam of red light. What will happen if the red light is replaced by the blue light?
1. | No change takes place. |
2. | Diffraction bands become narrower. |
3. | Diffraction bands become broader. |
4. | Diffraction pattern disappears. |
The phenomenon of polarisation justify which nature of light?
1. longitudinal
2. transverse
3. both
4. geometrical
If the momentum of a photon is p, then its energy is :
1. pc
2.
3.
4.
For non-relativistic speeds, the wavelength associated with an electron and its kinetic energy E are related as:
1.
2.
3.
4.
An electron at rest is acceleration by a potential difference of 600V. The de-Broglie wavelength associated with the electron is:
1.
2.
3.
4.