Doubtly
@Doubtly · Joined Feb 2021
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- What is the SI unit of amount of a substance ? Answer: The SI unit of amount of substance is the mole (symbol: mol). The mole is one of the seven SI base units. One mole is the amount of... 1
- How many particles are present in 1 mole of a substance ? The number of particles present in 1 mole is 6.022 × 10²³ It is Avogadro's number equal to 6.022×10²³ and is expressed as the symbol N_A. 1
- Calculate the molecular mass of the following in u. a. NH3 b. CH3 COOH c. C2 H5 OH A) NH_(3 ) _(molecular mass of )NH_(3 =(1 × atomic space mass space of space N ) ) + (3× atomic mass of H) =(1×14 u)+(3× 1u) =17 u B) CH_(3... 1
- How many grams does an atom of hydrogen weigh ? The weight of 1 atom of hydrogen is calculated as 1.66058 × 10⁻²⁴ grams. Explaination : we know that 1 molecule is made up of 6.023 ×10²³ at... 2
- Point out the difference between 12 g of carbon and 12 u of carbon 12 g of carbon is the molar mass of carbon and 12 u of carbon is the mass of one carbon atom since , 1u= 1 atomic mass unit =1.661 × 10⁻²⁷ k... 1
- A. State and explain Avogadro's law. In 1811, Avogadro proposed that equal volumes of all gases at the same temperature and pressure contain equal number of molecules According... 1
- 1. Choose the most correct option A sample of pure water, whatever the source always contains The answer is highlighted in question like this correct answer Answers ) Q1. Choose the most correct option A) a. 88.9 B) d. Na₂S, NaF C) a.... 1
- Formation of real image using a biconvex lens is shown below If the whole set up is immersed in water without disturbing the object and the The correct option is image disappers Explainnation :: from space 1over f=(μ_rel-1)(1over R₁-1over R₂) Focal length of lens will change henc... 1
- A load of mass M kg is suspended from a steel wire of length 2m and radius 1.0mm in Searle's apparatus The correct answer is option B) 3.00 mm Explaination :: 1
- 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+... 1
- A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. The correct answer is (1) 15 Explanation:: 1
- 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... 1
- 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 1
- 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 2
- 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 2
- The output of the given combination gates represents : 2) Nand gate is the correct answer 1
- 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... 1
- Which of the following polymer is used in the manufacture of wool laminates ? The correct answer is option (1) Urea formaldehyde resin Explanation:: 1