JEXPO 2019 Physics and Chemistry Answer Key Answer Key
JEXPO 2019 Physics and Chemistry Answer Key Answer Key
Note : JEXPO 2019 (WB Polytechnic) was of 100 MCQs among which 50 MCQs on Mathematics, 25 MCQs on Physics and 25 MCQs on Chemistry. Total of 100 MCQs was given in the puzzling form. I have enlisted here only 50 MCQs related to Physics and Chemistry.
[Solved] JEXPO 2019 – Mathematics Answer Key
Q.1) Rocket works on the principle of conservation of
(A) velocity
(B) mass
(C) linear momentum
(D) energy
Q.2) Definition of force comes from Newton’s
(A) First law of motion
(B) Second law of motion
(C) Third law of motion
(D) Law of Gravitation
JEXPO 2019 Physics and Chemistry Answer Key
Q.3) The resistance of the wire varies inversely as
(A) area of cross section
(B) resistivity
(C) length
(D) temperature
Q.4) Force required in accelerating a 3 kg mass at 5 m/s² and 4 kg mass at 4 m/s² will be
(A) zero in both cases
(B) same in both cases
(C) grater for 3 kg mass
(D) grater for 4 kg mass
Q.5) Substance showing electrical conductivity is
(A) Phosphorus
(B) Graphite
(C) Sulphur
(D) Bakelite
JEXPO 2019 Physics and Chemistry Answer Key
Q.6) The radius of curvature of mirror is 20 cm. The focal length is
(A) 20 cm
(B) 10 cm
(C) 40 cm
(D) 5 cm
Q.7) Graphite is used in nuclear reactor as
(A) Lubrican
(B) Fuel
(C) retarder of neutron velocity
(D) insulation lining of reacto
Q.8) ____ is located behind a convex mirror.
(A) Focal point
(B) Ray
(C) Real image
(D) The object
Q.9) The pitch of sound depends on
(A) amplitude
(B) wavelength
(C) frequency
(D) velocity
Q.10) The optical phenomena, twinkling of stars is due to
(A) atmospheric reflection
(B) total reflection
(C) atmospheric refraction
(D) total refraction
[Solved] JEXPO 2019 – Mathematics Answer Key
Q.11) Image formed by plane mirror is
(A) Real and erect
(B) Real and inverted
(C) Virtual and erect
(D) Virtual and inverted
JEXPO 2019 Physics and Chemistry Answer Key
Q.12) Silicon is a
(A) Semiconductor
(B) Insulator
(C) Non-conductor
(D) Conductor
Q.13) The curves representing Ohm’s law is a
(A) linear
(B) cosine function
(C) parabola
(D) hyperbola
Q.14) Example of physical change is
(A) Adding lime to water
(B) Consumption of automobile fuel
(C) Passing NH3 to CuSO4 solution
(D) Electric heating of filament in bulb
JEXPO 2019 Physics and Chemistry Answer Key
Q.15) Upthrust of body is equal to the
(A) weight of liquid
(B) mass of liquid
(C) weight of liquid displaced
(D) density of liquid
Q.16) Dimensional formula of relative density is
(A) [M0L0T0]
(B) [M0LT0]
(C) [MLT]
(D) [ML0T− 1]
Q.17) Acceleration is a vector quantity, which indicates that its value
(A) is always negative
(B) is always positive
(C) is zero
(D) can be positive, negative or zero
Q.18) The Supersonic speed of an aeroplane is expressed in
(A) Mach Number
(B) Decibel
(C) Hertz
(D) Watt
Q.19) The SI unit of electric power is
(A) Joule
(B) Ampere
(C) Watt
(D) Ohm
Q.20) In dry air at 0°C, the velocity of sound is about
(A) 367 m/s
(B) 331 m/s
(C) 3847 m/s
(D) 1505 m/s
[Solved] JEXPO 2019 – Mathematics Answer Key
Q.21) A concave mirror gives real, inverted and same size image if object is placed at
(A) focus
(B) infinity
(C) centre of curvature
(D) beyond centre of curvature
Q.22) In SONAR we use
(A) Ultrasonic waves
(B) Infrasonic waves
(C) Radio waves
(D) Audible sound waves
JEXPO 2019 Physics and Chemistry Answer Key
Q.23) What is the source of sound ?
(A) Transmitter
(B) Pressure of the speaker
(C) Vibration of an object
(D) Waves of an object
Q.24) A series circuit consists of three resistors with values of 140 Ω, 250 Ω and 220 Ω. The total resistance is
(A) 330 Ω
(B) 610 Ω
(C) 720 Ω
(D) 810 Ω
Q.25) Electric current originates from which part of an atom ?
(A) Nucleus
(B) Entire atom acting as a unit
(C) Positively charged protons
(D) Negatively charged electrons
JEXPO 2019 Physics and Chemistry Answer Key
Q.26) In Rutherford’s experiment on atomic model the screen beyond gold plate is made of
(A) Na2S
(B) CaC2
(C) AlN
(D) ZnS
Q.27) Metal preserved in kerosene
(A) Zn
(B) Mg
(C) Al
(D) Na
Q.28) Catalyst to convert NO from NH3 is
(A) Al
(B) Ni
(C) Pt-gauge
(D) Mo
JEXPO 2019 Physics and Chemistry Answer Key
Q.29) Tollen’s reagent is used to detect
(A) C3H8
(B) CH4
(C) Propyne
(D) C2H4
Q.30) Gas produced on reaction of Cu and cold (1 : 1) HNO3
(A) N2
(B) N2O
(C) NO2
(D) NO
[Solved] JEXPO 2019 – Mathematics Answer Key
Q.31) Ore of Al is
(A) Calamine
(B) Bauxite
(C) Haematite
(D) Magnetite
Q.32) Number of atoms in 0.28 gm CO is
(A) 6.023 × 1023
(B) 6.023 × 1022
(C) 1.206 × 1022
(D) 1.206 × 1023
Answer : 6.023 × 1021
JEXPO 2019 Physics and Chemistry Answer Key
Q.33) ____ have the same mass number, but different nuclear charge
(A) Isotones
(B) Isobars
(C) Isotopes
(D) Isoemtropic
Q.34) Which of the following ores contains maximum percentage of Uranium ?
(A) Rescolite
(B) Thorium
(C) Pitchblende
(D) Carnotite
Q.35) Gas turning clear limewater milky is
(A) CO2
(B) CO
(C) NH3
(D) HCl
Q.36) Gas used for welding purpose
(A) C2H2
(B) C2H4
(C) C4H10
(D) CH4
JEXPO 2019 Physics and Chemistry Answer Key
Q.37) Example of negative catalyst
(A) Ni – in hydrogenation of vegetable oil
(B) V2O5 in H2SO4
(C) H2SO4 in preparation of H2O2
(D) Mo in NH3 preparation
Q.38) NH3 not possible to obtain from
(A) Al + NaOH + NaNO3 + H2O
(B) NH4NO2 →∆
(C) NH4NO3 + NaOH
(D) Mg3N2 + H2O
JEXPO 2019 Physics and Chemistry Answer Key
Q.39) Isobaric atoms are
(A) 17Cl35 , 17Cl37
(B) C14 , 7N15
(C) 18Ar40 , 20Ca40
(D) 6C12 , 7N14
Q.40) Brass is an alloy of
(A) Al, Cu
(B) Cu, Ni
(C) Cu, Sn
(D) Cu, Zn
[Solved] JEXPO 2019 – Mathematics Answer Key
Q.41) Which gas dissolves in concentrated H2SO4 to give oleum ?
(A) CO2
(B) SO3
(C) SO2
(D) Cl2
Q.42) Metal that produces H2 on reaction with dilute HCl is
(A) Au
(B) Ag
(C) Pt
(D) Al
JEXPO 2019 Physics and Chemistry Answer Key
Q.43) Temporary hardness in water is caused by
(A) Fe(HCO3)2
(B) FeCl2
(C) CaSO4
(D) MgCl2
Q.44) Gas lighter than air is
(A) NH3
(B) H2S
(C) Cl2
(D) CO2
Q.45) Chemical fertilisers that makes soil acidic is
(A) Nitrolim
(B) (NH4)2SO4
(C) Urea
(D) KNO3
JEXPO 2019 Physics and Chemistry Answer Key
Q.46) Substance not used as indicator is
(A) Phenolphthalein
(B) Toluene
(C) Methyl red
(D) Methyl orange
Q.47) The oxide soluble both in caustic alkali and mineral acid solution
(A) SiO2
(B) MgO
(C) CaO
(D) SO2
Q.48) Mixture of iodine and NaCl is separated by
(A) filtration
(B) sublimation
(C) distillation
(D) dissolution
Q.49) Volume of Cl2 from reaction of 0.87 gm MnO2 and excess concentrated HCl at STP is
(A) 229 m
(B) 2.24 lit
(C) 22.4 lit
(D) 112 ml
JEXPO 2019 Physics and Chemistry Answer Key
Q.50) The gas not considered as Greenhouse Gas
(A) CO2
(B) CO
(C) PAN
(D) CH4
[Solved] JEXPO 2019 – Mathematics Answer Key
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