Evaluation Results

{"answer_key": [{"1(A)": {"questions": [{"question": "Heating effect of electric current is not observed in_", "answer key": "(C) electric motor", "maximum marks": "1", "question number": "1(A) i", "detail explaination": "1 mark for selecting the correct option (C) electric motor."}, {"question": "Which of the following is NOT a chemical change?", "answer key": "(B) Boiling water", "maximum marks": "1", "question number": "1(A) ii", "detail explaination": "1 mark for selecting the correct option (B) Boiling water."}, {"question": "___ is used for detecting and measuring electric current.", "answer key": "(B) Galvanometer", "maximum marks": "1", "question number": "1(A) iii", "detail explaination": "1 mark for selecting the correct option (B) Galvanometer."}, {"question": "While heating ice and water mixture, it is stirred continuously", "answer key": "(C) to have uniform heating.", "maximum marks": "1", "question number": "1(A) iv", "detail explaination": "1 mark for selecting the correct option (C) to have uniform heating."}, {"question": "When aluminium metal reacts with dilute hydrochloric acid, ___ gas is liberated.", "answer key": "(B) hydrogen", "maximum marks": "1", "question number": "1(A) v", "detail explaination": "1 mark for selecting the correct option (B) hydrogen."}], "maximum score": 5, "total question": 5, "total questions to attempt": 5}}, {"1(B)": {"questions": [{"question": "Find the odd one out Fuse wire, bad conductor,rubber gloves,generator", "answer key": "Generator. Others restrict flow of current while generator is used to produce current.", "maximum marks": "1", "question number": "1(B) i", "detail explaination": "1 mark for identifying 'generator' as the odd one out and providing a correct reason."}, {"question": "Define specific latent heat of fusion.", "answer key": "The amount of heat energy absorbed at constant temperature by unit mass of a solid to convert into liquid phase is called the specific latent heat of fusion.", "maximum marks": "1", "question number": "1(B) ii", "detail explaination": "1 mark for a correct and complete definition of specific latent heat of fusion."}, {"question": "Kinetic energy of a body of mass m on the surface of the earth: 1/2 * m * v_esc^2 :: kinetic energy of a body of mass m at infinite distance from earth : ___ Ans: zero Explanation:", "answer key": "Ans: zero", "maximum marks": "1", "question number": "1(B) iii", "detail explaination": "1 mark for stating 'zero' as the kinetic energy of a body at infinite distance from earth."}, {"question": "Complete the following table: Column A Column B Column C Mass kg Measure of inertia N Zero at the centre m/s^2 Depends on height", "answer key": "The completed table: Column A: Mass, Column B: kg, Column C: Measure of inertia; Column A: N, Column C: Zero at the centre; Column B: m/s^2, Column C: Depends on height.", "maximum marks": "1", "question number": "1(B) iv", "detail explaination": "1 mark for correct completion of all parts of the table."}, {"question": "What is meant by the term electropositivity of an element?", "answer key": "The tendency of an atom of an element to form cation by losing its valence electrons is called electropositivity of that element.", "maximum marks": "1", "question number": "1(B) v", "detail explaination": "1 mark for a correct and complete definition of electropositivity."}], "maximum score": 5, "total question": 5, "total questions to attempt": 5}}, {"2(A)": {"questions": [{"question": "The third period contains only eight elements even though the electron capacity of the third shell is 18.", "answer key": "i. The number of elements in the first three periods depends on the electron capacity of the shells and the law of electron octet. ii. The electron capacity of third shell is 18. So the third period should actually contain 18 elements. But it contains only 8 elements due to the law of electron octet.", "maximum marks": "2", "question number": "2(A) i", "detail explaination": "1 mark for stating the dependence on electron capacity and law of electron octet. 1 mark for explaining why the third period has 8 elements despite the 18-electron capacity, referring to the octet rule."}, {"question": "If the value of g suddenly becomes twice its value, it will become two times more difficult to pull a heavy object along the floor. Why?", "answer key": "i. In order to pull an object along the floor, it is necessary to do work against the force of friction. ii. The force of friction is directly proportional to the weight (mg). iii. If the value of g doubles, the weight of an object doubles, and therefore, the force of friction also doubles. iv. Thus, it will become two times more difficult to pull a heavy object along the floor.", "maximum marks": "2", "question number": "2(A) ii", "detail explaination": "0.5 mark for stating work against friction is needed. 0.5 mark for stating friction is proportional to weight (mg). 0.5 mark for explaining that doubling 'g' doubles weight and friction. 0.5 mark for concluding it becomes two times more difficult."}, {"question": "During winter season, we may have observed a white trail at the back of the aeroplane flying high in the clear sky or sometimes it may not get formed.", "answer key": "i. The ratio of actual mass of vapour content in the air for a given volume and temperature to that required to make the air saturated with vapour at that temperature is called the relative humidity. ii. The white trail is basically the vapour released by aeroplane engine condensing in sky to form cloud. iii. If the relative humidity of surrounding air is more then, we may get to observe this white trail at the back of the aeroplane flying high in the clear sky. iv. If the relative humidity of surrounding air is less then, either small sized white trail may get formed or it may not get formed at all.", "maximum marks": "2", "question number": "2(A) iii", "detail explaination": "0.5 mark for defining relative humidity. 0.5 mark for explaining the white trail formation. 0.5 mark for correlating high relative humidity with trail formation. 0.5 mark for correlating low relative humidity with no/small trail formation."}], "maximum score": 4, "total question": 3, "total questions to attempt": 2}}, {"2(B)": {"questions": [{"question": "The mass of a planet is 6 times the mass of earth and its radius is 3 times that of the earth. Considering acceleration due to gravity on earth to be 9.8 m/s², calculate the value of 'g' on the other planet.", "answer key": "Ans: Value of acceleration due to gravity on the other planet is 6.53 m/s². Explanation: Given: Mass of planet (Mp) = 6ME, radius of planet (Rp) = 3RE, gE = 9.8 m/s². To find: Acceleration due to gravity on the planet (gp). Formula: g = GM/R². Calculation: From formula, gp/gE = (Mp/ME) × (RE²/Rp²). gp = gE × (6ME/ME) × (RE²/(3RE)²). gp = 9.8 × 6/9 = 6.53 m/s².", "maximum marks": "2", "question number": "2(B) i", "detail explaination": "0.5 mark for correct 'Given' values. 0.5 mark for correct formula. 0.5 mark for correct substitution and calculation steps. 0.5 mark for final correct answer with units."}, {"question": "How much heat should be supplied to convert ice of mass 50 g at 0 °C into water at 40 °C?", "answer key": "Ans: Amount of heat energy that should be supplied is 6000 cal. Explanation: Given: Mass of ice/water (m) = 50 g, Change in temperature (ΔT) = 40 – 0 = 40 °C. Latent heat of melting of ice (Lmelt) = 80 cal/g, Specific heat of water (cw) = 1 cal/g °C. To find: Heat supplied (Q). Formulae: i. Heat required to convert ice at 0 °C into water at 0 °C is Q1 = mLmelt. ii. Heat required to raise temperature of water from 0 °C to 40 °C is Q2 = m × cw × ΔT. Calculation: From formula (i), Q1 = 50 × 80 = 4000 cal. From formula (ii), Q2 = 50 × 1 × (40 – 0) = 2000 cal. Total heat energy required Q = Q1 + Q2 = 4000 + 2000 = 6000 cal.", "maximum marks": "2", "question number": "2(B) ii", "detail explaination": "0.5 mark for correct 'Given' values. 0.5 mark for correct formulae (Q1 and Q2). 0.5 mark for correct calculation of Q1 and Q2. 0.5 mark for final correct total heat energy with units."}, {"question": "Find the difference between humid air and dry air.", "answer key": "If relative humidity of air is more than 60%, air is called humid, and if the relative humidity is less than 60%, the air is called dry air.", "maximum marks": "1", "question number": "2(B) iii(a)", "detail explaination": "1 mark for correctly defining both humid air and dry air based on relative humidity."}, {"question": "When 'm' kg of a substance of specific heat capacity ‘c' J/ °C kg cools from temperature ‘T' to ‘To', how much heat energy will be lost by it?", "answer key": "Heat energy lost by the substance = mc (T – T0) J", "maximum marks": "1", "question number": "2(B) iii(b)", "detail explaination": "1 mark for providing the correct formula for heat energy lost."}, {"question": "What is relative humidity? Write the formula for % relative humidity?", "answer key": "The ratio of actual mass of vapour content in the air for a given volume and temperature to that required to make the air saturated with vapour at that temperature is called the relative humidity. % relative humidity = (actual mass of water vapour content in the air in a given volume / mass of vapour needed to make the air saturated in that volume) × 100", "maximum marks": "2", "question number": "2(B) iv", "detail explaination": "1 mark for a correct definition of relative humidity. 1 mark for the correct formula for % relative humidity."}, {"question": "Which will spend more electrical energy? 500 W T.V. Set in 30 mins, or 600 W heater in 20 mins?", "answer key": "Ans: The energy consumed by T.V. set is more than that consumed by heater. Explanation: For T.V. set: Power = 500 W, Time = 30 min = 30 × 60 s. Energy (E1) = Power × time = 500 × 30 × 60 = 900 × 10³ J. For Heater: Power = 600 W, Time = 20 min = 20 × 60 s. Energy (E2) = 600 × 20 × 60 = 720 × 10³ J. Comparing E1 and E2, E1 > E2. Energy spent by T.V. set (E1) is greater.", "maximum marks": "2", "question number": "2(B) v", "detail explaination": "0.5 mark for correctly converting time to seconds for both. 0.5 mark for calculating energy for TV (E1). 0.5 mark for calculating energy for Heater (E2). 0.5 mark for correct comparison and conclusion."}], "maximum score": 6, "total question": 6, "total questions to attempt": 3}}, {"3": {"questions": [{"question": "What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.", "answer key": "i. The reaction in which oxidation and reduction takes place simultaneously is called a redox reaction. ii. Example: CuO + H2 → Cu + H2O. In this reaction, CuO loses oxygen to form Cu. This means that reduction of CuO takes place. H2 molecule takes up oxygen to form H2O. This means that oxidation of H2 takes place. Both the oxidation and reduction reactions always occur simultaneously.", "maximum marks": "2", "question number": "3 i(a)", "detail explaination": "0.5 mark for defining redox reaction. 0.5 mark for providing a correct example. 1 mark for explaining the oxidation and reduction parts in the example."}, {"question": "Identify oxidizing agent in the following reaction: 3Fe + 4H2O → Fe3O4 + 4H2", "answer key": "H2O", "maximum marks": "1", "question number": "3 i(b)", "detail explaination": "1 mark for correctly identifying H2O as the oxidizing agent."}, {"question": "Time versus temperature graph for two thermometers is plotted as shown below. For which of the thermometers, variation of temperature vs time, is depicted by plot (I)?", "answer key": "i. Thermometer B.", "maximum marks": "1", "question number": "3 ii(i)", "detail explaination": "1 mark for correctly identifying Thermometer B. Note: If diagram is missing, deduct marks."}, {"question": "Time versus temperature graph for two thermometers is plotted as shown below. What does the point Z in the above graph denote?", "answer key": "ii. Point Z denotes temperature at which density of water is maximum.", "maximum marks": "1", "question number": "3 ii(ii)", "detail explaination": "1 mark for correctly stating that Point Z denotes the temperature of maximum water density. Note: If diagram is missing, deduct marks."}, {"question": "Time versus temperature graph for two thermometers is plotted as shown below. In what temperature range, water displays anomalous behaviour?", "answer key": "iii. 0 °C to 4 °C.", "maximum marks": "1", "question number": "3 ii(iii)", "detail explaination": "1 mark for correctly stating the temperature range (0 °C to 4 °C). Note: If diagram is missing, deduct marks."}, {"question": "A thermally insulated pot has 200 g ice at temperature 0 °C. How much steam of 100 °C has to be mixed to it, so that water of temperature 40 °C will be obtained? (Given: Latent heat of melting of ice = 80 cal/g, latent heat of vaporisation of water = 540 cal/g, specific heat of water = 1 cal/g °C)", "answer key": "Ans: 41.38 g of steam of 100 °C should be mixed. Explanation: Given: Mass of ice/water (m) = 200 g, Change in temperature (ΔT) = 40 ° C. Lmelt = 80 cal/g, Lvap = 540 cal/g, cw = 1 cal/g °C. To find: Mass of steam (M). Formulae: Q1 = MLvap (steam to water at 100°C), Q2 = M × cw × ΔT (water 100°C to 40°C), Q3 = m × Lmelt (ice to water at 0°C), Q4 = m × cw × ΔT (water 0°C to 40°C). Calculation: Q1 + Q2 = Q3 + Q4. (M × 540) + (M × 1 × 40) = (200 × 80) + (200 × 1 × 40). M (540 + 40) = 16000 + 8000. 580 M = 240000. M = 240000 / 580 = 41.38 g.", "maximum marks": "3", "question number": "3 iii", "detail explaination": "0.5 mark for correctly identifying 'Given' values. 0.5 mark for writing all necessary formulae. 1 mark for setting up the heat exchange equation (Q1+Q2=Q3+Q4). 0.5 mark for correct substitution and calculation steps. 0.5 mark for final correct answer with units."}, {"question": "Two tungsten bulbs of wattage 100 W and 120 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?", "answer key": "Ans: The total current flowing in the main conductor is 1 A. Explanation: Given: Potential difference (V) = 220 V, Power of bulb 1 (P1) = 100 W, Power of bulb 2 (P2) = 120 W. To find: Total current (I). Formulae: i. P = VI ii. I = I1 + I2. Calculation: Since both bulbs are connected in parallel, potential difference is same. I1 = P1/V = 100/220 A. I2 = P2/V = 120/220 A. Total current I = I1 + I2 = 100/220 + 120/220 = (100+120)/220 = 220/220 = 1 A.", "maximum marks": "3", "question number": "3 iv", "detail explaination": "0.5 mark for correctly identifying 'Given' values. 0.5 mark for writing necessary formulae. 0.5 mark for calculating individual currents (I1 and I2). 0.5 mark for using the parallel circuit property (V same). 0.5 mark for applying I = I1 + I2. 0.5 mark for final correct answer with units."}, {"question": "State different types of wires used for carrying electric power supply in household circuits.", "answer key": "Following three types of wires are used for carrying electric power supply: i. phase wire or live wire ii. neutral wire iii. earth wire", "maximum marks": "1", "question number": "3 v(a)", "detail explaination": "1 mark for listing all three types of wires (phase/live, neutral, earth)."}, {"question": "Which pole of the magnetic needle will move towards wire XY once current starts flowing through the circuit?", "answer key": "North pole of the magnetic needle will move towards wire XY.", "maximum marks": "1", "question number": "3 v(b)", "detail explaination": "1 mark for stating that the North pole moves towards wire XY. Note: If the diagram is missing, deduct marks."}, {"question": "Working principle of electric generator", "answer key": "Magnetic effect of electric current", "maximum marks": "1", "question number": "3 v(c)", "detail explaination": "1 mark for stating 'Magnetic effect of electric current' as the working principle. (Note: The generally accepted principle for an electric generator is electromagnetic induction.)"}, {"question": "Atoms of two different elements are represented in the following diagram. Identify elements A and B.", "answer key": "i. A is magnesium and B is beryllium.", "maximum marks": "1", "question number": "3 vi(i)", "detail explaination": "0.5 mark for correctly identifying A as Magnesium. 0.5 mark for correctly identifying B as Beryllium. Note: If the diagram is missing, deduct marks."}, {"question": "Atoms of two different elements are represented in the following diagram. Do these elements belong to the same group? Justify your answer.", "answer key": "ii. Yes, they belong to the same group as they have same number of valence electrons.", "maximum marks": "1", "question number": "3 vi(ii)", "detail explaination": "0.5 mark for stating 'Yes, same group'. 0.5 mark for justifying with 'same number of valence electrons'. Note: If the diagram is missing, deduct marks."}, {"question": "Atoms of two different elements are represented in the following diagram. Which element is more electropositive? Explain with reason.", "answer key": "iii. Element A is more electropositive than element B. This is because electropositivity increases down the group with increase in atomic size.", "maximum marks": "1", "question number": "3 vi(iii)", "detail explaination": "0.5 mark for stating Element A is more electropositive. 0.5 mark for explaining the reason: electropositivity increases down the group due to increased atomic size. Note: If the diagram is missing, deduct marks."}, {"question": "Complete the following table. Element | Atomic No. | Electronic configuration | Type of element: Sodium | 11 | 2,8,1 | Metal; Magnesium | 12 | 2,8,2 | (blank); (blank) | 13 | 2,8,3 | Metal; Silicon | 14 | (blank) | Metalloid; Phosphorus | 15 | 2,8,5 | (blank); (blank) | (blank) | 2,8,6 | Nonmetal; Chlorine | 17 | 2,8,7 | Nonmetal", "answer key": "The completed table: Element: Sodium, Atomic No: 11, Electronic configuration: 2,8,1, Type of element: Metal; Element: Magnesium, Atomic No: 12, Electronic configuration: 2,8,2, Type of element: Metal; Element: Aluminium, Atomic No: 13, Electronic configuration: 2,8,3, Type of element: Metal; Element: Silicon, Atomic No: 14, Electronic configuration: 2,8,4, Type of element: Metalloid; Element: Phosphorus, Atomic No: 15, Electronic configuration: 2,8,5, Type of element: Nonmetal; Element: Sulphur, Atomic No: 16, Electronic configuration: 2,8,6, Type of element: Nonmetal; Element: Chlorine, Atomic No: 17, Electronic configuration: 2,8,7, Type of element: Nonmetal.", "maximum marks": "3", "question number": "3 vii", "detail explaination": "0.5 mark for each correctly filled blank entry (Magnesium's type, Aluminium's element/atomic no/config, Silicon's config, Phosphorus's type, Sulphur's element/atomic no/config). Total 6 correct entries, so 0.5 marks each for 6 items gives 3 marks. Note: If the table is missing, deduct marks."}, {"question": "Explain the factors affecting the value of gravitational acceleration of the earth 'g'.", "answer key": "The following factors affect the value of gravitational acceleration of the earth ‘g': i. Shape of the earth: a. The shape of the earth is not perfectly spherical. It is slightly flattened at the poles and bulged at the equator. b. As a result, the radius of the earth at the poles is less than that at the equator. c. Hence, the value of ‘g' is the highest at the poles (9.832 m/s²) and decreases slowly with decreasing latitude. It is the lowest at the equator (9.78 m/s²). ii. Height: a. As the height of an object from the surface of the earth increases, the distance between the object and the centre of the earth (r) increases. b. As a result, the value of ‘g’ decreases with increase in height. However, the decrease is rather small for heights which are small in comparison to the earth's radius. iii. Depth: a. The value of g is maximum on the surface of the earth. b. As depth of an object increases, the distance between the object and the centre of the earth (r) decreases. c. Along with the distance, the part of the earth which contributes towards the gravitational force felt by the object (M) also decreases. d. As a combined result of change in r and M, the value of g decreases as we go deep inside the earth. e. At the centre of the earth, the value of 'g' becomes zero.", "maximum marks": "3", "question number": "3 viii", "detail explaination": "1 mark for explaining the effect of 'Shape of the earth' on 'g'. 1 mark for explaining the effect of 'Height' on 'g'. 1 mark for explaining the effect of 'Depth' on 'g'."}], "maximum score": 15, "total question": 8, "total questions to attempt": 5}}, {"4": {"questions": [{"question": "What is meant by specific heat capacity? How will you prove experimentally that different substances have different specific heat capacities?", "answer key": "Definition: The amount of heat energy required to raise the temperature of a unit mass of an object by 1 °C is called the specific heat or specific heat capacity of that object. Experimental verification: i. Solid spheres of iron, copper and lead of equal mass are put into a beaker containing boiling water till they reach a temperature of 100 °C. ii. The spheres are then taken out together and immediately placed on a thick slab of wax. iii. It is seen that each sphere travels to a different depth in the wax slab. The iron sphere goes the deepest followed by copper and lead spheres. iv. The sphere that absorbs more heat from water goes the deepest because it supplies more heat to wax, causing more wax to melt. v. This proves that for equal rise in temperature, the three spheres absorbed different amounts of heat. The property that determines the amount of heat absorbed by an object is called as specific heat capacity.", "maximum marks": "5", "question number": "4 i", "detail explaination": "1 mark for a correct definition of specific heat capacity. 1 mark for describing the setup (equal mass spheres, boiling water). 1 mark for describing the placement on wax. 1 mark for observing the different depths and order (Iron deepest, then copper, then lead). 1 mark for the conclusion that different substances absorb different amounts of heat for the same temperature rise, proving different specific heat capacities. Note: If the diagram is missing, deduct marks."}, {"question": "Balance the following equation stepwise. H2S2O7(l) + H2O(l) → H2SO4(l)", "answer key": "Step I: Write the chemical equation: H2S2O7(l) + H2O(l) → H2SO4(l). Step II: Compare the number of atoms of the various elements present on the two sides of the equation. Reactants (Left side) H:4, S:2, O:8. Product (Right side) H:2, S:1, O:4. Step III: Choose the reactant or product having maximum number of atoms and equalize its atoms on both the sides. Equalize the number of atoms of remaining elements in the reactants and products. H2S2O7 has maximum number of atoms. First balance ‘S' as it requires a smaller factor. Number of S atoms: Initially Reactant (in H2S2O7) 2, Product (in H2SO4) 1. To balance Reactant 2, Product 1×2. Apply a factor '2' to the product 'H2SO4'. H2S2O7(l) + H2O(l) → 2H2SO4(l). Check whether the equation is balanced. The number of atoms of the elements in the reactants is same as the number of atoms of those elements in the product. Step IV: Write down the final balanced equation. H2S2O7(l) + H2O(l) → 2H2SO4(l).", "maximum marks": "3", "question number": "4 ii(a)", "detail explaination": "1 mark for correctly comparing initial atom counts. 1 mark for identifying the need to balance 'S' and applying the coefficient '2' to H2SO4. 1 mark for the final correctly balanced equation and stating all atoms are balanced."}, {"question": "Some more examples of redox reaction are as follows. Identify the reductants and oxidants from them. a. 2H2S + SO2 → 3S↓ + 2H2O b. MnO2 + 4HCl → MnCl2 + 2H2O + Cl2↑", "answer key": "a. H2S is reductant while SO2 is oxidant. b. HCl is reductant while MnO2 is oxidant.", "maximum marks": "2", "question number": "4 ii(b)", "detail explaination": "1 mark for correctly identifying reductant and oxidant in reaction (a). 1 mark for correctly identifying reductant and oxidant in reaction (b)."}], "maximum score": 5, "total question": 2, "total questions to attempt": 1}}], "usage_data": {"input_token_count": 2702, "output_token_count": 7327, "estimated_input_cost_inr": 0.07, "estimated_total_cost_inr": 1.6, "estimated_output_cost_inr": 1.53}, "total_marks": 40}