Sample Paper for Science Quiz Contest No-1

SAMPLE PAPER FOR SCIENCE QUIZ CONTEST NO-1

Names of students……………………………………………………….………………………………….……

School….……………………………...... ………………..…………………District…………………

QUESTIONS

1

Q. 1 The graph below represents the relationship between gravitational force and mass for objects near the surface of Earth.

The slope of the graph represents the

a) acceleration due to gravity

b) universal gravitational constant

c) momentum of objects

d) weight of objects

Q. 2 When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of a gold atom consists of ______.

a) deuterons

b) neutrons

c) protons

d) unoccupied space

Q.3 A proton has approximately the same mass as

a) a neutron

b) an alpha particle

c) a beta particle

d) an electron

Q. 4 When electrons in an atom in an excited state fall to lower energy levels, energy is

a) absorbed, only

b) released, only

c) neither released nor absorbed

d) both released and absorbed

Q. 5 A neutron has approximately the same mass as a

a) an alpha particle

b) a beta particle

c) an electron

d) a proton

Q. 6 Which symbols represent atoms that are isotopes?

a) C-14 and N-14

b) O-16 and O-18

c) I-131 and I-131

d) Rn-222 and Ra-222

Q. 7 Which element's ionic radius is smaller than its atomic radius?

a) neon

b) nitrogen

c) sodium

d) sulfur

Q. 8 An ion with 5 protons, 6 neutrons, and a charge of 3+ has an atomic number of

a) 5

b) 6

c) 8

d) 11

Q. 9 Which of the following is a binary compound?

a) hydrogen sulfide

b) hydrogen sulfate

c) ammonium sulfide

d) ammonium sulfate

Q. 10 Given the unbalanced equation: Al + O2 = Al2O3 When this equation is completely balanced using the smallest whole numbers, what is the sum of the coefficients?

a) 4

b) 7

c) 5

d) 9

Q. 11 Which of the following is a binary compound?

a) potassium chloride

b) ammonium chloride

c) potassium chlorate

d) ammonium chlorate

Q. 12 What is the total number of atoms represented in the formula CuSO4 . 5H2O?

a) 8

b) 13

c) 21

d) 27

Q. 13 What is the total number of atoms contained in 2.00 moles of nickel?

a) 58.9

b) 118

c) 6.02 x 1023

d) 1.2 x 1024

Q. 14 What is the percent by mass of oxygen in magnesium oxide, MgO?

a) 20%

b) 40%

c) 50%

d) 60%

Q. 15 What is the total number of moles of hydrogen gas contained in 9.03 x 1023

a) 1.5 moles

b) 2.00 moles

c) 6.02 moles

d) 9.03 moles

Q. 16 A compound is 86% carbon and 14% hydrogen by mass. What is the empirical formula for this compound?

a) CH

b) CH2

c) CH3

d) CH4

Q. 17 What is the total number of moles of H2SO4 needed to prepare 5.0 liters of a 2.0 M solution of H2SO4?

a) 2.5

b) 5.0

c) 10

d) 20

Q. 18 At STP, 32.0 liters of O2 contain the same number of molecules as

a) 22.4 L Ar

b) 28.0 L of N2

c) 32. 0 L of H2

d) 44.8 L of He

Q. 19 What is the molarity of a KF (aq) solution containing 116 grams of KF in 1.00 liter of solution?

a) 1.00 M

b) 2.00 M

c) 3.00 M

d) 4.00 M

Q. 20 What is the gram formula mass of (NH4)3PO4?

a) 113 g

b) 121 g

c) 149 g

d) 404 g

Q. 21 What is the empirical formula of a compound that contains 85% Ag and 15% F by mass?

a) AgF

b) Ag2F

c) AgF2

d) Ag2F2

Q. 22 Compared to the charge and mass of a proton, an electron has

a) the same charge and a smaller mass

b) the same charge and the same mass

c) an opposite charge and a smaller mass

d) an opposite charge and the same mass

Q.23 If the escape velocity of a rocket from the surface of the Earth is ve , then the escape velocity of the same rocket from the surface of a planet whose acceleration due to gravity as well as radius are 5 times that of the Earth is

a) ve

b) 25 ve

c) 5 ve

d) ve /5

Q. 24 The SI unit of density is

a) m3/kg

b) kg/m3

c) g/cm3

d) cm3/g

Q.25 Which of the following occurs during evaporation?

a) Steam and oxygen escape from the liquid bulk.

b) Molecules escape from the liquid surface.

c) Steam and oxygen escape from the liquid surface.

d) Molecules escape from the liquid bulk.

Q.26 ______is the heaviest natural element.

a) Lead

b) Mercury

c) Uranium

d) Radium

Q.27 A piece of plastic is rubbed with a cloth and is then found to be negatively charged. The most likely explanation of this that
a) Electrons are transferred from the cloth to the plastic
b) Plastic is always negatively charged
c) The cloth rubs electrons off the plastic
d) Positive ions are removed from the plastic

Q. 28 Which of the following is a scalar quantity?
a) Velocity
b) Retardation
c) Speed
d) Displacement

Q.29 When a convex lens is used as a magnifying glass the image is
a) real and upright
b) real and inverted
c) virtual and upright
d) virtual and inverted
Q. 30 Two plane mirrors are supported with their surfaces at right angles and a small object is placed between them. How many reflected images of this object can be seen in the mirrors?
a) 1
b) 2
c) 3
d) 4

Q.31 The image formed in a plane mirror is
a) real and the same size as the object
b) real and nearly the same size as the object
c) virtual and the same size as the object
d) virtual and the half the size of the object

Q. 32 Which of the following does not apply to sound waves?
a) They transmit energy
b) They result from vibration
c) They travel fastest in a vacuum
d) They can be diffracted
Q.33 What force is required to give a projectile weighing 450 N an acceleration of 500 m/s2?

a) 5.6 E 4 N

b) 2.3 E 4 N

c) 1.6 E 4 N

d) 8.7 E 4 N

Q.34 A plane is flying at 8000. m. If a package is dropped from the plane how fast would the package be traveling when it hits the ground?

a) 205.6 m/s

b) 396.0 m/s

c) 457.8 m/s

d) 120.4 m/s

Q. 35 A projectile is fired into the air and 12.6 seconds later hits the ground. With what speed was the projectile fired into the air?

a) 97.5 m/s

b) 14.6 m/s

c) 61.7 m/s

d) 38.6 m/s

Q.36 How many kilowatts are required to raise a weight of 25 N a distance of 8.0 m in 2.5 minutes?

a) 1.33 E - 3 kW

b) 2.63 E - 2 kW

c) 1.86 E 2 kW

d) 3.35 E -5 kW

Q.37 A suitcase is accidentally dropped from an airplane flying at an altitude of 3.2 E 4 m. With what final velocity does it strike the earth? (no air resistance of course)

a) 380 m/s

b) 350 m/s

c) 240 m/s

d) 790 m/s

Q.38 An elevator in the Empire State Building rises to the 70. floor in 43 seconds. If the height is 900. feet, what horsepower must be developed in order to lift 12 people averaging 160 lb each to this floor?

a) 57 hp

b) 89 hp

c) 63 hp

d) 73 hp

Q.39 How many seconds does it take a metal ball to drop 200 m from rest?

a) 6.39 s

b) 4.28 s

c) 8.58 s

d) 7.29 s

Q.40 The mass of a large steel ball is 1200 kg. What power is used in raising it to a height of 30. m if the work is performed in 14 seconds?

a) 2.5 E 4 W

b) 4.5 E 4 W

c) 8.5 E 3 W
d) 9.3 E 4 W

Q.41 An object weighing 450 pounds strikes the earth with a velocity of 145 ft/s. With what kinetic energy did it strike the earth?

a) 4.6 E 5 ft lb

b) 3.0 E 5 ft lb
c) 2.4 E 4 ft lb

d) 5.1 E 4 ft lb

Q.42 A projectile is launched at a speed of 24 m/s. The parachute fails and the projectile falls (free fall) back to earth. What is the total time the projectile is in flight?

a) 4.9 s
b) 3.2 s

c) 8.6 s
d) 9.7 s

Q.43 A toy airplane that is flying at 3.00 m/s speeds up to 19.0 m/s in 2.20 seconds due to a force of 6.95 E 2 N. Using this information what is the mass of the toy?

a) 7.27 g

b) 95.6 g

c) 38.2 g

d) 14.8 g

Q.44 A plane is traveling at a speed of 250 miles per hour at an altitude of 600 feet. How far before the target must the plane drop an object to insure it hits the target?

a) 6.12 mile

b) 1530 mile

c) 0.425 mile

d) 8.35 mile
Q.45 Which of the following is not affected by temperature

a) Normality

b) Formality

c) Molarity

d) Molality

Q.46 Third law of thermodynamics helps in the calculation of

a) Enthalpy change

b) Internal free energy change

c) Absolute entropies

d) Free energy changes

Q.47 A redox reaction is spontaneous in a given direction if

a) EMF is zero

b) EMF is negative

c) EMF is positive

d) EMF has nothing to do with the spontaneity

Q.48 The oxidation potential of Mg and Al are +2.37 and +1.66 volts respectively. The Mg in chemical reaction

a) will be replaced by Al

b) will replace Al

c) will not be able to replace Al

d) None of the above

Q.49 The free energy change in a photochemical reaction is

a) always zero

b) always negative

c) always positive

d) can be positive or negative

Q.50 Picric acid is

a) Trinitrotoluene

b) Trinitroaniline

c) A volatile liquid

d) 2,4,6-Trinitrophenol

Q.51 The Cannizzaro reaction is not given by

a) Trimethylacetaldehyde

b) Acetaldehyde

c) Benzaldehyde

d) Formaldehyde

Q.52 Acertaldehyde cannot show

a) Idoform test

b) Lucas test

c) Benedict’s test

d) Tollen’s test

Q.53 Azo dye test is given by

a) All amines

b) Only primary amines

c) Only primary aliphatic amines

d) Only primary aromatic amines

Q.54 Properties of the alkaline earth metals that increases with their atomic number is

a) ionisation energy

b) solubility of their hydroxides

c) solubility of their sulphates

d) electro-negativity

Q.55 Paramagnetism is the property of

a) Paired electrons

b) completely filled electronic subshells

c) Unpaired electrons

d) completely vacant electronic subshells

Q.56 Radioactive decay is reaction of

a) first order

b) second order

c) third order

d) zero order

Q.57 Which of the following atomic number of uranium is most radioactive?

a) 238

b) 235

c) 226

d) 248

Q.58 The colloidal sols are purified by

a) peptisation

b) coagulation

c) dialysis

d) flocculation

Q.59 Rice is deficient in

a) Lysine

b) Alanine

c) Glycine

d) Leucine

Q.60 Metabolism involves

a) Synthesis of molecules

b) Degradation of molecules

c) Both synthesis and degradation of molecules

d) None of the above

Q.61 The number of polypeptide chains in a molecule of haemoglobin is

a) One

b) Two

c) Four

d) Six

Q.62 Gulf weed is

a) Chalmydomonas

b) Sargassum

c) Fucus

d) Batrachospermum

Q.63 Botanical snakes are

a) Algae

b) Fungi

c) Pteridophytes

d) Bryophytes

Q.64 In eusporangiate ferns, the sporangia develop from

a) Group of initials

b) Single initials

c) 1-4 spores

d) Few to large number of spores

Q.65 Pyrenoids are the centre for formation of

a) Protein

b) Enzymes

c) Fat

d) Starch

Q.66 Which is not a fungal disease

a) Rust of coffee

b) Red rust of tea

c) Rust of wheat

d) White rust of crucifers

Q.67 Osmotrophs are

a) Fungi

b) Bacteria

c) Both (a) and (b)

d) Algae

Q.68 Transfer of genetic material with the help of virus is called

a) Transference

b) Transformation

c) Transduction

d) Transcription

Q.69 Yeast cells are rich in which of the following vitamins?

a) A

b) B

c) C

d) D

Q.70 Litmus was previously obtained from

a) Puff ball

b) Cetaria islandica

c) Rocella tinctoria

d) Cladonia rangifera

Q.71 Gills of mushroom take part in

a) Respiration

b) Enhancing buoyancy

c) Nutrition

d) Bearing spores

Q.72 Dikaryon formation is characteristic of

a) Ascomycetes and basidiomycetes

b) Phcomycetes and bsidiomycetes

c) Ascomycetes and phycomycetes

d) Phycomycets and zygomycetes

Q.73 Casparian strips occur in the cells of

a) Endodermis

b) Pericycle

c) Cortex

d) Epidermis

Q.74 Tunica corpus theory is meant for

a) Root apex

b) Root cap

c) Lateral meristem

d) Shoot apex

Q.75 Molybdenum is required for

a) Phloem transport

b) Xylem transport

c) Nitrogen Fixation

d) Flower induction

Q.76 Seepage of minerals from topsoil to subsoil is

a) Percolation

b) Leaching

c) Gravitational flow

d) Run-off

Q.77 Antherozoids of moss are

a) Short, curved and biciliate

b) Rod shaped, biciliate

c) Long and multiciliate

d) Short and multiciliate

Q.78 Cyathium inflorescence is found in

a) Compositae

b) Criciferae

c) Leguminosae

d) Euphorbiaceae

Q.79 Photomorphogenetic pigment is

a) Chlorophyll

b) Xanthophyll

c) Phycocyanin

d) Phytochrome

Q.80 Garner and Allard discovered

a) Phototropism

b) Photoperiodism

c) Photooxidation

d) Photomorphogenesis

Q. 81 Which of the following systems is NOT commutative?

a) Addition for whole numbers

b) Multiplication of integers

c) Subtraction of whole numbers

d) Addition for integers

Q. 82 A total of Rs 450 is divided into equal shares. If Anil receives four shares, Sunil receives three shares, and Pushpa receives the remaining two shares, how much money did Sunil receive?

a) Rs 100

b) Rs150

c) Rs 200

d) Rs 250

Q. 83 In a hockey league, 87 players play on seven different teams. Each team has at least 12 players. What is the largest possible number of players on any one team?

a)13

b) 14

c) 15

d) 21

Q. 84 When 20 is subtracted from -4, the result is

a) 24

b) 16

c) -16

d) -24

Q. 85 The Pentagon building in Washington, D.C., is shaped like a regular pentagon. If the length of one side of the Pentagon is represented by n + 2, its perimeter would be represented by

a) 5n + 10

b) 5n + 2

c) n + 10

d) 10n

Q. 86 The ratio of the corresponding sides of two similar squares is 1 to 4. What is the ratio of the area of the smaller square to the area of the larger square?

a) 1:2

b) 1:4

c) 1:8

d) 1:16

Q. 87 A fair coin is thrown in the air four times. If the coin lands with the head up on the first three tosses, what is the probability that the coin will land with the head up on the fourth toss?

a) 0

b) 1/16

c) 1/2

d) 1/8

Q. 88 A special lottery is to be held to select the student who will live in the only deluxe room in a dormitory. There are 100 seniors, 150 juniors, and 200 sophomores who applied. Each senior's name is placed in the lottery 3 times; each junior's name, 2 times; and each sophomore's name, 1 time. What is the probability that a senior's name will be chosen?

a)

b)

c)

d)

Q. 89 Study of preservation of the life or study of organisms at low temperature is

a) Kalology

b) Malacology

c) Crybiology

d) Dermatology

Q. 90 The term ‘Protista’ was coined by

a) E. Haeckel

b) John Ray

c) Linnaeus

d) G. Cuvier

Q. 91 Branch of science related to the improvement of the human race through laws of heredity

a) Hereditary

b) Genetics

c) Eugenics

d) Euthenics

Q. 92 Archaeopteryx called a connecting link, carried the characters of

a) Reptiles and Birds

b) Reptiles and Mammals

c) Fishes and amphibians

d) Amphibians and Reptiles

Q. 93 The body of sponge consists of

a) Epithelial tissue only

b) All four types of tissues

c) Only epithelial and connective tissues

d) Non-structurally organized tissue

Q. 94 Hydra can digest all type of foods except

a) Protein

b) Fats

c) Starch

d) Sugars

Q. 95 Which of the following parasites has no intermediate host

a) Fasciola

b) Ascaris

c) Taenia

d) Bacterium

Q. 96 In earthworm following help in locomotion-

a) Chloragogen cells

b) Spermathecal

c) Clitellum

d) Setae

Q. 97 In cockroach the excretory organs are

a) Malpighian corpuscles

b) Nephridia

c) Malpighian tubules

d) Solenocytes (Flame cells)

Q.98 Which of the following is unmatchable?

a) Sea pen, Sea fan, Coral, Jelly fish

b) Pipe fish, Globe fish, Jelly fish, Gold fish

c) Sea-star, Sea-urchin, Sea anemone, Sea Cow

d) All of these

Q.99 Whose eggs are smallest amongst the vertebrates?

a) Shark

b) Frogs

c) Mammals

d) Birds

Q.100 Centre for respiration is

a) Medulla oblongata

b) Diencephalon

c) Olfactory lobe

d) Cerebrum

1

Answer Sheet Sample Paper - 1

SAMPLE PAPER FOR SCIENCE QUIZ CONTEST NO-2

Names ………………………………………………………………………………………………..…………………………………………………

Institution name….……………………………………………………………. City /District………………….…………………………………..

QUESTIONS

1

Q.1A body is moving with a constant speed  in a circle of radius r. Its angular acceleration is

a) r

b) /r

c) Zero

d) r2

Q.2A player caught a cricket ball of mass 150 gm moving at a speed of 20 m/s. if the catching process be complete in 0.1 s, the force of the blow exerted by the ball on the hands of the player will be:

a) 0.3 N

b) 30 N

c) 300 N

d) 3000 N

Q.3When a steady torque is acting on a body, the body is

a) Continues in its state of rest or uniform motion along a straight line

b) Gets linear acceleration

c) Gets angular acceleration

d) Rotate at a constant speed

Q.4Sudden fall of atmospheric pressure by a large amount indicates

a) Storm

b) Rain

c) Fair weather

d) Cold wave

e)

Q.5A liquid does’t wet the surface of a solid if the angle of contact is

a) Zero

b) An acute one

c) 45

d) an obtuse one

Q.6An electric bulb is rated 220 volt and 100 watt. Power consumed by it when operated on 100 volt is

a) 25 watt

b) 75 watt

c) 90 watt

d) 50 watt

Q.7The law of electromagnetic induction have been used in the construction of a

a) Galvanometer

b) Voltmeter

c) Electric motor

d) Generator

Q.8Triode valve can be used at

a) Modulator

b) Amplifier

c) Demodulator

d) All the above

Q.9If x is a real number such that x (x2 + 1), (-1/2)x2, 6 are three consecutive terms of an AP then the next two consecutive term of the AP are

a) 14,6

b) –2,-10

c) 14,22

d) none of these

Q.10If ,  are roots of equation (x –a ) ( x –b ) = c, c  0, then the roots of the equation ( x -  ) ( x - ) + c = 0 are

a) a,c

b) b,c

c) a,b

d) a + c, b + c

Q.11If  is an imaginary cube root of unity then (1 +  - 2 )7 equal

a) 128 

b) –128 

c) 128 2

d) - 128 2

Q.12The number of triangles that can be formed with 10 points as vertices, n of them being collinear, is 110. Then n is

a) 3

b) 4

c) 5

d) 6

Q.13A piece of paper in the shape of a sector of a circle of radius 10 cm and of angle 216 just covers the lateral surfaces of a right circular cone of vertical angle 2. Then sin  is

a) 3/5

b) 4/5

c) 3/4

d) None of these

Q.14Bhindawas Bird Sanctuary in Haryana is located in

a) Karnal

b) Jhajjar

c) Mahendergarh

d) Ambala

Q.15The number of points with integral coordinates that are interior to the circle x2 +y2 = 16 is

a) 43

b) 49

c) 45

d) 51

Q.16The primitive of the function x  cos x  when /2  x   is given by

a) cos x + x sin x

b) –cos x – x sin x

c) x sin x- cos x

d) None of these

Q.17A coin is tossed 7 times. Each time a man gets head, the probability that he wins the toss on more occasions is

a) 1/4

b) 5/8

c) 1/2

d) None of these

Q.1820 teachers of a school either teach mathematics or physics. 12 of them teach mathematics while 4 teach both the subjects. Then the number of teachers teaching physics only is

a) 12

b) 8

c) 16

d) None of these

Q.19In the value of 100 the number of zeros at the end is

a) 11

b) 22

c) 23

d) 24

Q.20Transduction was discovered by:

a) Griffith

b) Stanley and Lederberg

c) Pasture

d) Zinder and Lederberg

Q.21Cork cambium is the example of

a) Lateral meristem

b) Primary meristem

c) Apical meristem

d) Intercalary meristem

Q22 The best conductor of heat among liquid is

a) water

b) mercury

c) ether

d) alcohol

Q.23What type of mirror can used to obtain the real image of an object?

a) plane mirror

b) concave mirror

c) convex mirror

d) no mirror can produce a real image

Q.24The technique of recording and reproducing three- dimensional images of the objects is known as

a) autoradiography

b) lexicography

c) holography

d) photography

Q.25A woman voice is shriller than a man’s due to

a) higher frequency

b) higher amplitude

c) lower frequency

d) weak vocal chords

Q.26The loudness of a sound wave is determined by its

a) amplitude

b) frequency

c) wavelength

d) speed

Q.27The speed of sound will be highest in

a) dry air at 0oC

b) dry air at 30 oC

c) humid air at 0 oC

d) humid air at 30 oC

Q.28Echoes are produced due to

a) reflection of sound

b) refraction of sound

c) diffraction of sound

d) polarization of sound

Q.29The frequency of a sound is related to its

a) amplitude

b) pitch

c) loudness

d) quality

Q.30Which of the following is the particle-antiparticle pair?

a) proton, neutron

b) photon, electron

c) electron, positron

d) neutrino, neutron

Q.11 kilobyte and 1 megabyte are respectively equal to

a) 1024 bytes and 1000 kilobytes

b) 1000 bytes and 100 kilobytes

c) 1000 bytes and 10000 bytes

d) 1024 bytes and 100 kilobytes

Q.32The term ‘program’ refers to

a) a sequence of instructions

b) the computer’s internal design

c) any information stored in the memory

d) any information processed by the computer

Q.33C, C++, JAVA are the examples of

a)commercial computer brand

b) a computer’s internal parts

c) programming languages

d)types of secondary memory devices

Q.34Pure water from sea can be obtained by the process of

a) filtration

b) distillation

c) evaporation

d)fractional distillation

Q.35Common salt is obtained form sea water by the process of

a) evaporation

b) sublimation

c) crystallization

d) filtration

Q.36Washing soda is

a) sodium chloride

b) hydrated sodium carbonate

c) sodium bicarbonate

d) calcium carbonate

Q.37Carborundum is a compound of

a) Ca

b) Ge

c) Si

d) S

Q.38Chemically baking soda is

a) calcium phosphate

b) sodium bicarbonate

c) sodium chloride

d) baker’s yeast

Q.39Lime water contains

a)sodium hydroxide

b) calcium chloride

c) sodium carbonate

d) calcium hydroxide

Q.40Diamond is chemically

a) a mixture of metal carbonates

b) pure carbon

c) a pure form of sand

d) a mixture of Ca and Mg

Q.41The gas inside an electric bulb is

a) air

b) oxygen

c) nitrogen

d) carbon dioxide

Q.42The process that does not involve evolution of CO2 is

a) combustion

b) respiration

c) fermentation

d) photosynthesis

Q.43Of the following the content of carbon is minimum in

a) steel

b) wrought iron

c) pig iron

d) cast iron

Q.44The substance made from only carbon is

a) sugar

b) acetic acid

c) graphite

d) methane

Q.45The metal generally mixed with gold while making ornaments is

a) zinc

b) iron

c) silver

d) copper

Q.46The greatest numbers of compounds are formed by the element is

a) hydrogen

b) carbon

c) oxygen

d) nitrogen

Q.47Heavy water

a) contains more dissolved air

b) contains more dissolved minerals and salts

c) contains deuterium in place of hydrogen

d) contains organic impurities

Q.48Natural rubber is a polymer of

a) ethylene

b) vinyl chloride

c) isoprene

d) styrene

Q.49Chemically cane sugar is

a) lactose

b) glucose

c) sucrose

d) starch

Q.50Milk is an example of

a) emulsion

b) gel

c) suspension

d) foam

Q.51Hypo, used in photography, is chemically

a) silver bromide

b) sodium thiosulphate

c) sodium phosphate

d) silver nitrate

Q.52Cinnabar is an ore of

a) copper

b) mercury

c) iron

d)lead

Q.53The pure crystalline form of silica used in scientific apparatus for passing ultraviolet light is called

a) soda glass

b) pyrex glass

c) corning glass

d) quartz glass

Q.54Camphor can easily be purified by the process of

a) sublimation

b) distillation

c) crystallization

d) sedimentation

Q.55The most commonly used metal in the pure form or as an alloy in domestic appliances is

a)iron

b) aluminium

c) copper

d) zinc

Q.56The gas used for artificial ripening of the green fruit is

a) ethylene

b) ethane

c) carbon dioxide

d) acetylene

Q.57The first metal used by man was