Q1
mcq
1 mark
A device that converts electrical energy into mechanical energy is
- A. Electric generator
- B. Electric motor
- C. Galvanometer
- D. Voltmeter
Correct Answer: B —
Solution
The correct choice is B. An electric motor converts electrical energy into mechanical energy. A generator does the reverse (mechanical to electrical). A galvanometer detects the presence of current, and a voltmeter measures potential difference.
Q2
mcq
1 mark
A mirror forms an erect and enlarged image of an object. Then the type of the mirror and the nature of the image respectively are
- A. convex mirror and virtual image
- B. concave mirror and real image
- C. plane mirror and real image
- D. concave mirror and virtual image
Correct Answer: D —
Solution
The correct choice is D. A concave mirror produces an enlarged, erect, and virtual image when the object is placed between the pole (P) and the principal focus (F). Convex and plane mirrors cannot form enlarged images of real objects.
Q3
mcq
1 mark
The power plant that generates electricity without using the turbines is
- A. Thermal power plant
- B. Hydro power plant
- C. Solar power plant
- D. Nuclear power plant
Correct Answer: C —
Solution
The correct choice is C. Solar cells convert solar energy directly into electricity without moving parts like turbines. Thermal, hydro, and nuclear power plants all require turbines to convert kinetic/thermal energy into mechanical energy for power generation.
Q4
mcq
1 mark
Imagine, you are holding a straight current carrying conductor as per the right hand thumb rule. If the thumb is upward, then the direction of the field lines of the magnetic field is
- A. downward
- B. upward
- C. anti-clockwise
- D. clockwise
Correct Answer: C —
Solution
The correct choice is C. According to the right-hand thumb rule, if the thumb points in the direction of the current (upward), the fingers curl in the direction of the magnetic field lines, which, viewed from above, is anti-clockwise.
Q5
short answer
1 mark
Draw the symbol diagram of rheostat used in electric circuit.
Solution
A rheostat is represented by a resistor symbol with an arrow pointing across it or a slider moving along the resistor: [Resistor Symbol] with a diagonal arrow pointing at it, or a zigzag line with an arrow touching the top.
Q6
short answer
1 mark
Observe the figure and mention the direction of the force acting on the current carrying conductor AB. Name the rule that helped you to find the direction of the force.
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Q7
short answer
2 marks
Name any two fossil fuels and mention any two disadvantages of using fossil fuels.
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Q8
short answer
2 marks
$1000\text{ J}$ of heat is produced each $2\text{ seconds}$ in a $5\ \Omega$ resistor. Find the potential difference across the resistor.
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Q8
short answer
2 marks
OR: A wire of given material having length '$l$' and area of cross-section '$A$' has a resistance of '$4\ \Omega$'. Find the resistance of another wire of the same material having length '$l/2$' and area of cross-section '$2A$'.
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Q9
short answer
3 marks
What is meant by the 'aperture' of a spherical mirror ? Mention the four uses of a concave mirror.
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Q9
short answer
3 marks
OR: a) What is meant by the power of a lens ? Write the formula used to find the power of a lens. What is the SI unit of power of a lens? b) If the focal lengths of two lenses 'A' and 'B' are $+ 0.50\text{ m}$ and $- 0.40\text{ m}$ respectively. Mention the types of these lenses in the same order.
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Q10
short answer
3 marks
Observe the given diagram: Explain the experiment related to this diagram. What conclusions can be drawn from this experiment?
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Q11
short answer
3 marks
Draw the ray diagram for the image formation by a convex lens, when the object is placed at $2F_1$. With the help of the ray diagram mention the position and the nature of the image formed. [$F_1$: Principal focus of the lens]
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Q12
long answer
4 marks
a) A bread-toaster rated $350\text{ W}$ is used for $15\text{ hours}$ a day. An electric iron box rated $250\text{ W}$ is used for $5\text{ hours}$ a day. Calculate the cost of using these appliances for $30\text{ days}$, if the cost of $1\text{ kWh}$ is Rs. $4$. b) In which method the resistors $R_1$ and $R_2$ could be connected so that the equivalent resistance of that electric circuit becomes low? What is the change in the value of current in the circuit by this type of connection?
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Q13
long answer
5 marks
a) How does the lens of human eye accommodate to see the nearby objects and the distant objects ? Explain.
b) Explain the formation of rainbow in the nature.
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Q14
mcq
1 mark
Mendeleev’s periodic table is constructed on the basis of
- A. Atomic number
- B. Electronic configuration of an atom
- C. Atomic size
- D. Atomic mass.
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Q15
mcq
1 mark
Chips manufacturers, flush bags of chips with nitrogen gas because, to
- A. prevent corrosion of chips
- B. prevent chips from getting oxidised
- C. make chips undergo rancidity
- D. prevent the chips from getting reduced.
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Q16
short answer
1 mark
Name the product produced when calcium oxide reacts with water.
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Q17
short answer
1 mark
Name the ions responsible for acidic and basic natures of the substances.
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Q18
short answer
1 mark
Why are detergents more suitable for cleansing clothes in hard water ?
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Q19
short answer
1 mark
Ionic compounds have high melting point and boiling point. Why ?
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Q20
short answer
2 marks
In a homologous series, the first member of hydrocarbon group has the molecular formula $CH_4$. Then find out the molecular formula of the fourth member and write two types of structural formula of it.
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Q21
short answer
2 marks
What are alloys ? Name the constituent elements present in bronze and solder metal.
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Q22
short answer
2 marks
Add same amount of barium chloride solution to a test tube containing 5 ml of sodium sulphate solution. Then
i) Which insoluble white precipitate is formed ?
ii) Name the ions responsible for the formation of white precipitate.
iii) Mention the type of chemical reaction that took place here.
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Q23
long answer
3 marks
Draw the diagram of arrangement of the apparatus used to show the action of steam on metal. Label the following parts :
i) Metal sample
ii) Delivery tube.
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Q24
short answer
2 marks
What are ores ? Write the respective methods used to convert sulphide and carbonate ores of metals into their oxides.
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Q24
long answer
3 marks
The elements are arranged in the increasing order of their atomic masses in the below given table. Observe it and answer the following questions :
Sa Re Ga Ma Pa Dha Ni
H Li Be B C N O F Na
i) Name the elements that belong to the same group.
ii) State the law that helps to group these elements.
iii) Write two limitations of the same law.
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Q25
long answer
3 marks
a) Identify unsaturated hydrocarbons in the following carbon compounds and write their structural formula. $C_6H_6, C_5H_{12}, C_2H_5OH, C_2H_2$.
b) Write the difference between esterification and saponification.
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Q26
long answer
4 marks
a) Explain the manufacturing of bleaching powder. Write any two uses of it.
b) A strong solution of sodium hydroxide is added to the strong solution of hydrochloric acid. What is the nature of the salt solution formed here ? Write a balanced chemical equation for this reaction.
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Q27
mcq
1 mark
Producers of aquatic eco-system are
- A. algae
- B. small fishes
- C. larvae
- D. protozoa.
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Q28
mcq
1 mark
Biological process that has been shown in the diagram is
- A. production of progenies by fragmentation method
- B. production of progenies by multiple fission method
- C. regeneration of tissues by development in specialised cells
- D. asexual reproduction by vegetative propagation.
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Q29
long answer
3 marks
a) Write electron dot structure of oxygen molecule.
b) Carbon atom does not form $C^{-4}$ anion and $C^{+4}$ cation. Why ?
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Q30
short answer
1 mark
Mention the two importances of ‘Recycling’ in controlling environmental pollution.
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Q31
short answer
2 marks
What needs of the local people are fulfilled by the forest?
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Q32
short answer
2 marks
Draw the diagram showing the structure of nephron and label ‘glomerulus’.
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Q33
short answer
Name the elements that belong to the same group.
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Q33
short answer
2 marks
Student ‘A’ tells to Student ‘B’ that the wing of bird and arm of human are analogous organs. Student ‘B’ replies both of them are homologous organs. Whose answer is correct? Justify your answer with suitable reasons.
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Q34
short answer
State the law that helps to group these elements.
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Q34
long answer
3 marks
Draw the diagram showing the structure of the human brain and label the following parts: i) Mid-brain ii) Pons.
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Q35
long answer
3 marks
Round, green colour seeds producing pea plant ($RR yy$) is crossed with wrinkled, yellow colour seeds producing pea plant ($rr YY$). Show the result of $F_2$ generation with the help of a checker board and mention the ratio of varieties of plants.
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Q36
short answer
Identify unsaturated hydrocarbons in the following carbon compounds and write their structural formula. $C_6H_6$, $C_5H_{12}$, $C_2H_5OH$, $C_2H_2$.
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Q36
long answer
3 marks
“Reaching to sexual maturation is an essential event with respect to mammals like humans.” Substantiate this statement.
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Q37
short answer
Write the difference between esterification and saponification.
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Q38
short answer
Write electron dot structure of oxygen molecule.
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Q39
short answer
Carbon atom does not form $C^{-4}$ anion and $C^{+4}$ cation. Why?
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Q40
short answer
Explain the manufacturing of bleaching powder. Write any two uses of it.
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Q41
short answer
A strong solution of sodium hydroxide is added to the strong solution of hydrochloric acid. What is the nature of the salt solution formed here? Write a balanced chemical equation for this reaction.
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Q49
long answer
3 marks
How are the traits of organisms classified as ‘dominant’ and ‘recessive’ traits? The experiences of an individual acquired during its life-time cannot be passed on to its progeny. Why?
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Q51
long answer
As the growth advances in a climbing plant (creeper) that appears as the plant is moving towards a particular direction. How?
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Q52
long answer
Explain the necessity of chemical communication in animals.
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Q53
long answer
Compare the functions of xylem tissue with that of phloem tissue.
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Q54
long answer
Explain the process of exchange of gases that take place through stomata in plants.
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Q55
long answer
How is the structure of human heart supportive in transporting oxygenated blood and deoxygenated blood? Explain.
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Q56
long answer
In humans, how is the digested food absorbed by the blood? Mention the function of blood in transporting necessary materials.
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