All questions

• The image of an object, formed by a plano-convex lens at a distance of 8m behind the lens, is real and is one third the size of the object. Correct option is d) 3m Explaination:: μ =λ₀over λ_m=3over2 1over f=(μ-1)over R=1over 2R 1over f=1over V-1over u 1over8-(1over24)=1over2R 3+... Physics 1 answer
• An electromagnetic wave can be produced, when charge is Amoving with a constant velocity Correct option is D) both B and C An accelerated charge is the source of electromagnetic waves (EMWs). When the charge is in a circular moti... Physics 1 answer
• A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. The correct answer is (1) 15 Explanation:: Physics 1 answer
• The radius in kilometre to which the present radius of earth (R = 6400 km) to be compressed so that the escape velocity is increased 10 times is ____________ 64 km solution:: Escape velocity = √(2GMover R) we know mass remain unchanged V_e' over V_e = √(R_eover R_e') 10Vover eover Vover e =√(6400o... Physics 1 answer
• A Carnot's engine working between 400 K and 800 K has a work output of 1200 J per cycle. (2) 2400 J Explaination:: Wover Q_in=1-T₂over T₁=1-1over2=1over2 1200over Q_in=1over2 Q_in=2400 J Physics 1 answer
• A polyatomic ideal gas has 24 vibrational modes. What is the value of gamma ? (2) 1.03 is the correct option Explaination :: f= 3+3 +24 (vibrational modes) =30 γ = 1+2over30=16over15 γ=1.067 Physics 2 answers
• Which level of the single ionized carbon has the same energy as the ground state energy of hydrogen atom ? Correct answer is option (1) 6 Physics 2 answers
• The output of the given combination gates represents : 2) Nand gate is the correct answer Physics 1 answer
• For what value of displacement the kinetic energy and potential of a simple harmonic oscillation become equal ? The correct option is (3) x= ±Aoversqrt2 Explaination:: potential energy = 1over2kx²=1over2mω²( x²) Kinetic energy = 1over2m(ω√( A²-x²))² As... Physics 1 answer
• Explain with diagram the boiling point elevation in terms of vapour pressure lowering ? The boiling point of a liquid is the temperature at which the vapour pressure of the liquid becomes equal to the atmospheric pressure. For E... Rotational Dynamics 2 answers
• What is osmotic pressure ? Chemistry 12th osmosis is a flow of solvent through a semipermeable membrane into the solution. The direction of osmosis can be reversed by applying a pres... Rotational Dynamics 2 answers
• Which of the following polymer is used in the manufacture of wool laminates ? The correct answer is option (1) Urea formaldehyde resin Explanation:: Random 1 answer
• The green house gas/es is (are : (A) Carbon dioxide (B) Oxygen (C) Water vapour (D) Methane (1) (A), (C) and (D) only The green house gases are CO_(2 ), H₂O(vapour) & CH₄ Random 1 answer
• The equivalents of ethylene diamine required to replace the neutral ligands from the coordination 2 is the correct answer for this question [Co(NH₃)₄Cl₂]Cl + 2en → [Co(en)₂Cl₂]Cl + 4NH₃ Random 1 answer
• Complete combustion of 750 g of an organic compound provides 420 g of CO2 and 210 g of H2O. 3 is the answer . This is a Liebeig method for estimation of carbon and H-percentage % of H-element . Random 1 answer
• A certain element crystallises in a bcc lattice of unit cell edge, length 27ºÅ. If the same element Answer: 33 Explanation:: for bcc structure 4r=sqrt3a r=sqrt3aover4 …1 For FCC structure 4r=sqrt2a r=sqrt2aover4 …2 From 1 and 2 Random 1 answer
• The type pollution that gets increased during the day time and in the presence of O3 is : (2) Oxidising smog In presence of ozone(O3), oxidising smog gets increased during the day time because automobiles and factories produce mai... Random 1 answer
• Which of the following reaction DOES NOT involve Hoffmann bromamide degradation ? The correct answer is option 3) This reaction does not involve haffmann bromanide degradation Rest all options involve haffmann bromamide de... Random 1 answer
• The process that involves the removal of sulphur from the ores is : jee main march 2021 1) roasting Removal of sulphur from the ore is done by Roasting. Random 1 answer
• Which among the following pairs of Vitamins is stored in our body relatively for longer duration ? (2) Vitamin A and Vitamin D Random 2 answers
• In chromatography technique, the purification of compound is independent of : Correct answer is option (2) Physical state of the pure compound In chromotography technique, the purification of a compound is independent... Random 1 answer
• Which of the following is Lindlar catalyst ? (1) Cold dilute solution of KMnO4 (2) Partially deactivated palladised charcoal Random 2 answers
• A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The correct answer is option 2 ) Bi Random 2 answers
• Lactic acid and glycolic acid are the monomers used for preparation of polymer The correct answer is option B) Dextrin Chemistry 2 answers