Q1
mcq
1 mark
Convex mirrors are used in
- A. torches
- B. rear view mirrors of vehicles
- C. search-lights
- D. shaving mirrors
Correct Answer: B —
Solution
Convex mirrors are used as rear-view mirrors in vehicles because they always form a virtual, erect, and diminished image, providing a wider field of view. Torches and search-lights use concave mirrors (to produce parallel beams), and shaving mirrors use concave mirrors (to produce an enlarged image).
Q2
mcq
1 mark
The sun is visible to us about two minutes before the actual sunrise and about two minutes even after the actual sunset because of atmospheric
- A. refraction of light
- B. reflection of light
- C. scattering of light
- D. dispersion of light
Correct Answer: A —
Solution
The sun is visible two minutes before actual sunrise and two minutes after actual sunset due to atmospheric refraction. As sunlight enters the Earth's atmosphere, it bends due to varying densities of air layers, causing the sun to appear higher than its actual position.
Q3
mcq
1 mark
A current carrying rod is placed between the poles of a horse-shoe magnet. For the maximum displacement of the rod the angle between the direction of electric current and the direction of magnetic field must be
- A. 0°
- B. 45°
- C. 90°
- D. 180°
Correct Answer: C —
Solution
The force on a current-carrying conductor in a magnetic field is given by $F = I L B \sin(\theta)$. The force is maximum when $\sin(\theta)$ is maximum, which occurs when $\theta = 90^\circ$.
Q4
short answer
1 mark
Draw a symbol diagram of a resistor used in an electric circuit.
Solution
The symbol for a resistor is represented by a zig-zag line: $--/\/\/\/\--$
Q5
short answer
1 mark
“Two magnetic field lines do not intersect each other.” Justify.
Solution
If two magnetic field lines were to intersect, there would be two different directions for the magnetic field at the point of intersection. This is impossible as a compass needle can only point in one direction at any given point.
Q6
short answer
1 mark
Observe the circuit diagram given below. Mention the direction of magnetic field that forms around the point P and around the point Q.
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Q7
short answer
2 marks
Explain Newton’s experiment that shows the recombination of spectrum of white light.
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Q8
short answer
2 marks
Write any two differences between near-sighted (Myopic) and far-sighted (Hypermetropic) eyes.
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Q9
long answer
3 marks
Draw the ray diagram of image formed when an object is kept at $2F_1$ of the convex lens. With the help of the ray diagram write the position and nature of the image. ($F_1$ : Principal focus of the lens)
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Q10
long answer
3 marks
a) State Ohm’s law.
b) Write the factors on which the resistance of a conductor depends.
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Q11
long answer
3 marks
a) What factor helps for determining the relative strength of a magnetic field?
b) What is solenoid? How is an electromagnet prepared by using it?
OR
In domestic electric circuits,
a) What is the function of earth wire?
b) What precautions should be taken to avoid overloading?
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Q12
long answer
4 marks
a) How is an ammeter and a voltmeter connected to an electric circuit? Mention their function.
b) “In domestic electric circuit, the electrical appliances are generally connected in parallel.” Give reasons.
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Q13
long answer
4 marks
The radius of curvature of a spherical mirror is 36 cm. Find its focal length. A candle of 5 cm length is placed at a distance of 27 cm in front of a convex mirror of the same focal length. Mention the position and nature of the image and also find the size of the image formed.
OR
The focal length of a spherical mirror is 10 cm. Find its radius of curvature. An object of 4 cm size is placed at 20 cm in front of a concave mirror of the same focal length. At what distance from the mirror should a screen be placed in order to obtain a sharp image of the object? Mention the nature of the image formed and also find the size of the image.
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Q13
long answer
The radius of curvature of a spherical mirror is 36 cm. Find its focal length. A candle of 5 cm length is placed at a distance of 27 cm in front of a convex mirror of the same focal length. Mention the position and nature of the image and also find the size of the image formed.
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Q14
short answer
What factor helps for determining the relative strength of a magnetic field ?
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Q14
mcq
1 mark
Correct statement related to the soaps among the following is, soaps
- A. easily give excess of foam in hard water
- B. form insoluble precipitate in hard water
- C. easily clean oils like dirt in hard water
- D. are sodium salts of sulphonic acid
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Q15
short answer
What is solenoid ? How is an electromagnet prepared by using it ?
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Q15
mcq
1 mark
$CuO + H_{2} \xrightarrow{Heat} Cu + H_{2}O$. In this chemical reaction,
- A. hydrogen is reduced to form water
- B. exchange of ions took place between the reactants
- C. copper oxide is oxidised to form copper
- D. copper oxide is reduced to form copper
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Q16
short answer
In domestic electric circuits, what is the function of earth wire ?
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Q16
short answer
1 mark
Mention any two measures for preventing corrosion of iron.
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Q17
short answer
In domestic electric circuits, what precautions should be taken to avoid overloading ?
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Q17
short answer
1 mark
How is concentrated acid diluted ?
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Q18
short answer
How is an ammeter and a voltmeter connected to an electric circuit ? Mention their function.
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Q18
short answer
2 marks
What is rancidity ? Mention any two methods of preventing rancidity.
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Q19
short answer
In domestic electric circuit, the electrical appliances are generally connected in parallel. Give reasons.
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Q19
short answer
2 marks
Give reason : a) Zinc oxide is called as an amphoteric oxide b) Sodium metal is stored in kerosene.
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Q20
short answer
Complete the following oxidation reaction and name the functional group that is found in the product : $CH_{3}CH_{2}OH \xrightarrow{Alkaline \ KMnO_{4} \ or \ acidified \ K_{2}Cr_{2}O_{7} + Heat}$
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Q21
long answer
The focal length of a spherical mirror is 10 cm. Find its radius of curvature. An object of 4 cm size is placed at 20 cm in front of a concave mirror of the same focal length. At what distance from the mirror should a screen be placed in order to obtain a sharp image of the object ? Mention the nature of the image formed and also find the size of the image.
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Q21
short answer
3 marks
Draw the diagram of the arrangement of apparatus used to show the electrolytic refining of copper. Label the following parts : i) Cathode ii) Impurities.
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Q22
short answer
3 marks
Write the chemical equations for the following reactions. i) Quicklime is reacted with water ii) Zinc pieces are added to copper sulphate solution iii) Sodium chloride solution is added to silver nitrate solution.
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Q23
short answer
4 marks
a) $NaOH, Ca(OH)_{2}, H_{2}$ and $Cl_{2}$ materials are given to you. By using which of these materials, you can prepare bleaching powder ? Write the chemical name and one use of the bleaching powder. b) i) How do you identify a solution as basic solution by using blue litmus paper ? ii) Under what condition does a farmer treat the soil of his field with slaked lime ?
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Q24
long answer
5 marks
a) Write any two differences between saturated and unsaturated carbon compounds. b) What are structural isomers ? Write the structural isomers of butane. c) Write the electron dot structure of methane molecule.
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Q25
mcq
1 mark
The information source for making proteins in the cells is
- A. Gene
- B. Chromosome
- C. DNA
- D. Ribosome
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Q26
mcq
1 mark
Blood sugar level increases : Undersecretion of insulin hormone :: Swelling of the neck : ..................... .
- A. Undersecretion of thyroxine hormone
- B. More secretion of insulin hormone
- C. More secretion of thyroxine hormone
- D. Excess intake of iodine.
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Q27
mcq
1 mark
Type of asexual reproduction that occurs in spirogyra is
- A. Budding
- B. Regeneration
- C. Binary fission
- D. Fragmentation
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Q28
short answer
2 marks
Give reason : a) Gold is used to make jewellery b) Ionic compounds in the solid state do not conduct electricity.
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Q28
short answer
1 mark
What is the function of ozone layer ?
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Q30
short answer
1 mark
The events that occur during photosynthesis are given below. Write these events in correct order.
i) Splitting of water molecules into hydrogen and oxygen
ii) Absorption of light energy by chlorophyll
iii) Conversion of carbon dioxide to carbohydrates
iv) Conversion of light energy to chemical energy.
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Q31
short answer
2 marks
How do auxins promote the growth of tendrils of climbing plants around a support ?
OR
How does our body respond when adrenaline is secreted into the blood ?
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Q32
short answer
3 marks
Balance the following chemical equations : i) $H_{2} + O_{2} \rightarrow H_{2}O$ ii) $Na_{2}CO_{3} + HCl \rightarrow NaCl + H_{2}O + CO_{2}$ iii) $N_{2} + H_{2} \rightarrow NH_{3}$
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Q32
short answer
2 marks
Construct a food chain using the organisms ; snake, frog, grass and grasshopper. Which organism has more accumulation of harmful chemicals in this food chain ?
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Q33
short answer
2 marks
Draw the diagram showing the germination of pollen on stigma and label ‘ovary’.
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Q34
long answer
3 marks
What is the role of the following enzymes in human alimentary canal ?
i) Trypsin
ii) Amylase
iii) Lipase
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Q35
long answer
3 marks
Justify the following statements :
a) Sexual type of reproduction leads to more variations.
b) In woman’s uterus the role of placenta is significant for the development of foetus.
OR
a) How does menstruation occur in women ?
b) In male reproductive system the testes are located outside the abdominal cavity in scrotum. Why ?
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Q36
long answer
3 marks
Draw the diagram showing the structure of human brain. Label the following parts :
i) Hypothalamus
ii) Medulla
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Q37
long answer
3 marks
Round green colour ( RRyy ) seeds producing pea plant is crossed with wrinkled yellow colour seeds ( rrYY ) producing pea plant. Show the result of $F_2$ generation with the help of a checker board and write the ratio of varieties of plants.
OR
a) Explain the sex determination of a child in human beings.
b) How can the traits of organisms be decided as either dominant or recessive ?
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Q38
long answer
4 marks
a) Explain briefly the role of haemoglobin pigments present in our blood.
b) What are the different strategies of excretion found in plants ?
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