SCIENCE
,
, DELHI
2023 CBSE Solved Paper
Time allowed : 3 hours Maximum Marks : 80
GENERAL INSTRUCTIONS:
Read the following instructions carefully and strictly follow them:
(i) This question paper consists of 39 questions. All questions are compulsory.
(ii) Question paper is divided into FIVE sections – Section A, B, C, D and E.
(iii) In section A – question number 1 to 20 are multiple choice questions (MCQs) carrying one mark each.
(iv) In section B – question number 21 to 26 are very short answer (VSA) type questions carrying two marks each. Answer to
these questions should be in the range of 30 to 50 words.
(v) In section C – question number 27 to 33 are short answer (SA) type questions carrying three marks each. Answer to these
questions should be in the range of 50 to 80 words.
(vi) In section D – question number 34 to 36 are long answer (LA) type questions carrying five marks each. Answer to these
questions should be in the range of 80 to 120 words.
(vii) In section E – question number 37 to 39 are of 3 source based/case based units of assessment carrying four marks each
with sub-parts.
(viii) There is no overall choice. However, an internal choice has been provided in some sections.
(a) X = Ca ; Y = CaO; Type of reaction = Decomposition
Section-A
(b) X = Mg ; Y = MgO; Type of reaction = Combination
1. When Sodium bicarbonate reacts with dilute hydrochloric (c) X = Al ; Y = Al2O3; Type of reaction = Thermal
acid, the gas evolved is: (1 Mark) decomposition
(a) Hydrogen; it gives pop sound with burning match stick. (d) X = Zn ; Y = ZnO; Type of reaction = Endothermic
(b) Hydrogen; it turns lime water milky. 4. Acid present in tomato is: (1 Mark)
(c) Carbon dioxide; it turns lime water milky. (a) Methanoic acid (b) Acetic acid
(d) Carbon dioxide; it blows off a burning match stick (c) Lactic acid (d) Oxalic acid
with a pop sound.
5. Sodium hydroxide is termed an alkali while Ferric
2. When aqueous solutions of potassium iodide and lead hydroxide is not because: (1 Mark)
nitrate are mixed, an insoluble substance separates out. (a) Sodium hydroxide is a strong base, while Ferric
The chemical equation for the reaction involved is: hydroxide is a weak base.
(1 Mark) (b) Sodium hydroxide is a base which is soluble in water
(a) KI + PbNO3 → PbI + KNO3 while Ferric hydroxide is also a base but it is not
(b) 2KI + Pb(NO3)2 → PbI2 + 2KNO3 soluble in water.
(c) KI + Pb(NO3)2 → PbI + KNO3 (c) Sodium hydroxide is a strong base while Ferric
hydroxide is a strong acid.
(d) KI + PbNO3 → PbI2 + KNO3
(d) Sodium hydroxide and Ferric hydroxide both are
3. A metal ribbon ‘X’ burns in oxygen with a dazzling white strong bases but the solubility of Sodium hydroxide
flame forming a white ash ‘Y’. The correct description of in water is comparatively higher than that of Ferric
X, Y and the type of reaction is: (1 Mark) hydroxide.
, 6. The name of the salt used to remove permanent hardness 12. The number of chromosomes in parents and offsprings of a
of water is: (1 Mark) particular species undergoing sexual reproduction remain
(a) Sodium hydrogen carbonate (NaHCO3) constant due to: (1 Mark)
(b) Sodium chloride (NaCl) (a) doubling of chromosomes after zygote formation.
(c) Sodium carbonate decahydrate (Na2CO3⋅10H2O) (b) halving of chromosomes after zygote formation.
1 (c) doubling of chromosomes before gamete formation.
(d) Calcium sulphate hemihydrate (CaSO4⋅ H2O)
2
(d) halving of chromosomes at the time of gamete
7. The electron dot structure of chlorine molecule is: formation.
(1 Mark) 13. Two LED bulbs of 12W and 6W are connected in series. If
xx xx xx
(a) x x (b) x x
x the current through 12W bulb is 0.06A the current through
x Cl x Cl xx x Cl x Cl
xx xx x 6W bulb will be: (1 Mark)
xx xx (a) 0.04A (b) 0.06A
(c) x x (d) x x
x Cl Cl x Cl x Cl
xx (c) 0.08A (d) 0.12A
8. Observe the following diagram and identify the process 14. The correct pattern of magnetic field lines of the field
and its significance from the following options: (1 Mark) produced by a current carrying circular loop is:(1 Mark)
Water vapour
Leaf
(a) N S
–
+
Water
(a) Evaporation: Maintains water contents in leaf cells.
(b) Transpiration: Creates a suction force which pulls
water inside the plant. (b) N S
(c) Excretion: Helps in excreting out waste water from
the plant.
(d) Translocation: Helps in transporting materials from
one cell to another. –
+
9. Opening and closing of stomata is due to: (1 Mark)
(a) High pressure of gases inside the cells.
(b) Movement of water in and out of the guard cells.
(c) Stimulus of light in the guard cells.
(d) Diffusion of CO2 in and out of the guard cells. (c) N S
10. A cross between pea plant with white flowers (vv) and pea
plant with violet flowers (VV) resulted in F2 progeny in –
which ratio of violet (VV) and white (vv) flowers will be: +
(1 Mark)
(a) 1 : 1 (b) 2 : 1
(c) 3 : 1 (d) 1 : 3
11. In plants the role of cytokinin is: (1 Mark) (d) N S
(a) Promote cell division.
(b) Wilting of leaves. –
(c) Promote the opening of stomatal pore. +
(d) Help in the growth of stem.
4 SCIENCE
,
, DELHI
2023 CBSE Solved Paper
Time allowed : 3 hours Maximum Marks : 80
GENERAL INSTRUCTIONS:
Read the following instructions carefully and strictly follow them:
(i) This question paper consists of 39 questions. All questions are compulsory.
(ii) Question paper is divided into FIVE sections – Section A, B, C, D and E.
(iii) In section A – question number 1 to 20 are multiple choice questions (MCQs) carrying one mark each.
(iv) In section B – question number 21 to 26 are very short answer (VSA) type questions carrying two marks each. Answer to
these questions should be in the range of 30 to 50 words.
(v) In section C – question number 27 to 33 are short answer (SA) type questions carrying three marks each. Answer to these
questions should be in the range of 50 to 80 words.
(vi) In section D – question number 34 to 36 are long answer (LA) type questions carrying five marks each. Answer to these
questions should be in the range of 80 to 120 words.
(vii) In section E – question number 37 to 39 are of 3 source based/case based units of assessment carrying four marks each
with sub-parts.
(viii) There is no overall choice. However, an internal choice has been provided in some sections.
(a) X = Ca ; Y = CaO; Type of reaction = Decomposition
Section-A
(b) X = Mg ; Y = MgO; Type of reaction = Combination
1. When Sodium bicarbonate reacts with dilute hydrochloric (c) X = Al ; Y = Al2O3; Type of reaction = Thermal
acid, the gas evolved is: (1 Mark) decomposition
(a) Hydrogen; it gives pop sound with burning match stick. (d) X = Zn ; Y = ZnO; Type of reaction = Endothermic
(b) Hydrogen; it turns lime water milky. 4. Acid present in tomato is: (1 Mark)
(c) Carbon dioxide; it turns lime water milky. (a) Methanoic acid (b) Acetic acid
(d) Carbon dioxide; it blows off a burning match stick (c) Lactic acid (d) Oxalic acid
with a pop sound.
5. Sodium hydroxide is termed an alkali while Ferric
2. When aqueous solutions of potassium iodide and lead hydroxide is not because: (1 Mark)
nitrate are mixed, an insoluble substance separates out. (a) Sodium hydroxide is a strong base, while Ferric
The chemical equation for the reaction involved is: hydroxide is a weak base.
(1 Mark) (b) Sodium hydroxide is a base which is soluble in water
(a) KI + PbNO3 → PbI + KNO3 while Ferric hydroxide is also a base but it is not
(b) 2KI + Pb(NO3)2 → PbI2 + 2KNO3 soluble in water.
(c) KI + Pb(NO3)2 → PbI + KNO3 (c) Sodium hydroxide is a strong base while Ferric
hydroxide is a strong acid.
(d) KI + PbNO3 → PbI2 + KNO3
(d) Sodium hydroxide and Ferric hydroxide both are
3. A metal ribbon ‘X’ burns in oxygen with a dazzling white strong bases but the solubility of Sodium hydroxide
flame forming a white ash ‘Y’. The correct description of in water is comparatively higher than that of Ferric
X, Y and the type of reaction is: (1 Mark) hydroxide.
, 6. The name of the salt used to remove permanent hardness 12. The number of chromosomes in parents and offsprings of a
of water is: (1 Mark) particular species undergoing sexual reproduction remain
(a) Sodium hydrogen carbonate (NaHCO3) constant due to: (1 Mark)
(b) Sodium chloride (NaCl) (a) doubling of chromosomes after zygote formation.
(c) Sodium carbonate decahydrate (Na2CO3⋅10H2O) (b) halving of chromosomes after zygote formation.
1 (c) doubling of chromosomes before gamete formation.
(d) Calcium sulphate hemihydrate (CaSO4⋅ H2O)
2
(d) halving of chromosomes at the time of gamete
7. The electron dot structure of chlorine molecule is: formation.
(1 Mark) 13. Two LED bulbs of 12W and 6W are connected in series. If
xx xx xx
(a) x x (b) x x
x the current through 12W bulb is 0.06A the current through
x Cl x Cl xx x Cl x Cl
xx xx x 6W bulb will be: (1 Mark)
xx xx (a) 0.04A (b) 0.06A
(c) x x (d) x x
x Cl Cl x Cl x Cl
xx (c) 0.08A (d) 0.12A
8. Observe the following diagram and identify the process 14. The correct pattern of magnetic field lines of the field
and its significance from the following options: (1 Mark) produced by a current carrying circular loop is:(1 Mark)
Water vapour
Leaf
(a) N S
–
+
Water
(a) Evaporation: Maintains water contents in leaf cells.
(b) Transpiration: Creates a suction force which pulls
water inside the plant. (b) N S
(c) Excretion: Helps in excreting out waste water from
the plant.
(d) Translocation: Helps in transporting materials from
one cell to another. –
+
9. Opening and closing of stomata is due to: (1 Mark)
(a) High pressure of gases inside the cells.
(b) Movement of water in and out of the guard cells.
(c) Stimulus of light in the guard cells.
(d) Diffusion of CO2 in and out of the guard cells. (c) N S
10. A cross between pea plant with white flowers (vv) and pea
plant with violet flowers (VV) resulted in F2 progeny in –
which ratio of violet (VV) and white (vv) flowers will be: +
(1 Mark)
(a) 1 : 1 (b) 2 : 1
(c) 3 : 1 (d) 1 : 3
11. In plants the role of cytokinin is: (1 Mark) (d) N S
(a) Promote cell division.
(b) Wilting of leaves. –
(c) Promote the opening of stomatal pore. +
(d) Help in the growth of stem.
4 SCIENCE
