Maharashtra State Board
- H. Which properties of solvents are useful for solvent extraction? Organic compound must be more soluble in the organic solvent, than in water. Solvent should be immiscible with water and be able to form two... 1
- G. Give names of two materials used as stationary phase in chromatography. names of two materials used as stationary phase in chromatography. alumina silica gel 1
- F. What will happen if the upper outlet of the condenser is connected to the tap instead of the lower outlet? It is necessary to cool the condenser with cool water for proper functioning of condenser. If tap is connected to the upper outlet then jack... 2
- The sum of two numbers is 128 and their difference is 16. Find the numbers. Let the two numbers be x and y According to 1^st condition , x+y=128 ------1 According to 2nd condition , x-y=16 --------2 Adding equation 1... 1
- 5 Chairs and 4 Tables Together Cost ₹5600, While 4 Chairs and 3 Tables Together Cost ₹ 4340. Find the Cost of Each Chair and that of Each Table Video solution:: https://youtu.be/mG1XSNDtBig Text Solution Let the cost of a chair be ₹ x and that of a table be ₹ y, then 5x + 4y = 5600 …... 1
- 5 books and 7 pens together cost Rs 79 whereas 7 books and 5 pens together cost Rs 77, find the total cost of 1 book and 2 pens. Let the cost of a book be Rs x and that of a pen be Rs y. Then, 5x + 7y = 79 .....(i) 7x + 5y = 77 ....(iii) Multiplying equation (i) by 5 a... 1
- Shabana’s age 10 year hence will be twice as Juhi’s present age. The correct answer is shabanas age is 26 years and juhis age is 18 years Video solution::: https://youtu.be/g0836O7_m4A 1
- Identify from the following reactions the reactants that undergo oxidation and reduction A. Fe + S → FeS Here , Fe is oxidised from 0 to +2, while S is reduced from 0 to -2 Fe undergoes oxidation (as losing electrons) Sulphur und... 1
- 5. Observe the following picture a write down the chemical reaction with explanation. The picture given shows the corrosion of iron. The chemical formula of rust is Fe₂O₃.H₂O. The rust on iron does not form by a simple reactio... 1
- d. It is recommended to use air tight container for storing oil for long time It is recommended to use air tight container for storing oil for long time because, When oil comes in contact with air, it undergoes oxidati... 1
- c.While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to... 1
- b. It takes time for pieces of Shahabad tile to disappear in HCl, but its powder disappears rapidly When HCl is added to Shahabad stone effervescence of CO₂ is formed. The CO₂effervescence is formed slowly with the pieces of Shahabad tiles... 1
- a.When the gas formed on heating limestone is passed through freshly prepared lime water, the lime water turns milky i. When limestone (CaCO₃) is heated; it undergoes decomposition reaction giving calcium oxide (CaO) and carbon dioxide (CO₂) as products. ii... 1
- d. Displacement reaction 3. Explain the following terms with examples. The reaction in which the place of the ion of a less reactive element in a compound is taken by another more reactive element by formation o... 1
- c. Balanced equation 3. Explain the following terms with examples. A chemical equation in which the number of atoms of the elements in the reactant is same as the number of atoms of the elements in the produ... 1
- b. Combination reaction 3. Explain the following terms with examples. When two or more reactants combine in a reaction to form a single product, it is called a combination reaction. Example:: When HCl vapours s... 1
- A big dumb-bell is prepared by using a uniform rod of mass 60 g and length 20 cm. Two identical solid spheres of mass 50 g Answer: I = 46000\ mathrmg cm² = 4.6×10⁻³\ mathrmkg m² Given: rod M_r = 60\ g , L = 20\ cm ; each sphere M_s = 50\ g , R_s = 10\ cm . Distan... 1
- A flywheel used to prepare earthenware pots is set into rotation at 100 rpm. It is in the form of a disc Given : f_(1 )= 100 rpm, f₂= 80 rpm, M =10 kg, R = 0.4m, m = 1.6kg I₁=I_(wheel )= 1/2 MR² = 1/2(10)(0.4)² ^( )= 0.8 kg m² MI of the wheel an... 1
- The road in the question 14 above is constructed as per the requirements. Given : r=72m, θ= 78°4’ , μ_s=0.8, g= 10m/s^(2 ), tanθ= tan78^(°)4’ =5 V_min =√(rg(tanθ-μ_s/1+μ_stanθ)) V_min= √(72×10(5-0.8/1+(0.8((5))) v_... 1
- A metallic ring of mass 1 kg has moment of inertia 1 kg m2 when rotating about one of its diameters The MI of the thin ring about its diameter, Ir = 1/2MR² = 1 kg\ m² Since the ring is melted and recast into a thin disc of same radius R, th... 1
- State and explain the principle of conservation of angular momentum. Use a suitable illustration. Do we use it in our daily life? When? Law (or principle) of conservation of angular momentum : The angular momentum of a body is conserved if the resultant external torque on the... 1
- Derive an expression that relates angular momentum with the angular velocity of a rigid body. Consider a rigid body rotating with a constant angular velocity w about an axis through the point O and perpendicular to the plane of the fi... 1
- State the conditions under which the theorems of parallel axes and perpendicular axes are applicable. The theorem of parallel axis is applicable to any body of arbitrary shape. The moment of inertia (MI) of the body about an axis through the... 1
- Using the energy conservation, derive the expressions for the minimum speeds at different locations along a Consider a particle of mass m attached to a string and revolved in vertical circle of radius r, At every instant of motion there are only tw... 2