Q1
mcq
1 mark
The device used to measure the rate of current in a circuit is
- A. Ammeter
- B. Voltmeter
- C. Galvanometer
- D. Battery
Correct Answer: A —
Solution
An ammeter is specifically designed to measure the rate of flow of electric current (amperes) in a circuit. Voltmeters measure potential difference (voltage), galvanometers detect small currents, and batteries are sources of electric energy, not measuring devices.
Q2
mcq
1 mark
Observe the given figure. Identify the eye defect indicated in this figure.
- A. Presbyopia
- B. Hypermetropia
- C. Myopia
- D. Cataract
Correct Answer: C —
Solution
In the provided image, the light rays are converging at a point in front of the retina. This is characteristic of myopia (nearsightedness), where the eyeball is too long or the lens is too powerful, causing images of distant objects to focus before the retina.
Q3
mcq
1 mark
A light ray enters to rarer medium from a denser medium. Then the speed of that light ray
- A. decreases and bends towards the normal
- B. increases and bends away from the normal
- C. decreases and bends away from the normal
- D. increases and bends towards the normal
Correct Answer: B —
Solution
When light travels from a denser to a rarer medium, its speed increases. Due to this change in speed, it bends away from the normal line.
Q4
mcq
1 mark
The inner wall of the solar cooker is painted black. Because black colour
- A. reflects light
- B. converges solar rays
- C. prevents from rusting
- D. absorbs more heat
Correct Answer: D —
Solution
Black surfaces are excellent absorbers of thermal radiation. Painting the inner wall of a solar cooker black ensures that the maximum amount of solar heat energy is absorbed, which is then used to cook the food inside.
Q5
short answer
1 mark
Write the symbols of the following components used in an electric circuit.
i) Rheostat
ii) Wires crossing without joining
Solution
i) Rheostat: A zig-zag line or rectangle with an arrow passing through it or touching the top. ii) Wires crossing without joining: Two lines crossing each other, with one line having a small semi-circular loop over the point of intersection.
Q6
short answer
1 mark
What does the thumb indicate in the right hand thumb rule ?
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Q7
short answer
2 marks
Light enters from air to benzene having refractive index 1.50. Calculate the speed of light in benzene.
( Speed of light in air : $3 \times 10^8 \text{ ms}^{-1}$ )
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Q7
short answer
2 marks
OR
A concave lens has focal length of 12 cm. At what distance should the object from the lens be placed so that it forms an image at 9 cm from the lens ?
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Q8
short answer
2 marks
Name the major constituent of biogas and write the properties of biogas.
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Q8
short answer
2 marks
OR
List the hazards of nuclear power generation.
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Q9
long answer
3 marks
State Ohm’s law. On which factors does the resistance of a conductor depend ? Mention the SI unit of electric power.
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Q9
long answer
3 marks
OR
State Joule’s law of heating. How is fuse connected in the circuits ? Name the metal used in the filament and the gas filled in electric bulb.
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Q10
long answer
3 marks
The resistors $R_1$, $R_2$ and $R_3$ have the values 10 $\Omega$, 20 $\Omega$ and 60 $\Omega$ respectively, which have been parallelly connected to a battery of 24 V in an electric circuit. Then calculate the following :
i) The current flowing through each resistor
ii) The total current in the circuit
iii) The total resistance of the circuit.
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Q11
long answer
3 marks
Draw the ray diagram for the image formation in a convex lens when the object is placed beyond $2F_1$. Mention the position and nature of the image formed.
[$F_1$ : Principal focus of the lens ]
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Q12
long answer
4 marks
a) What is solenoid ? Write the properties of the magnetic field lines formed around a current carrying solenoid.
b) What is alternating current ? Electric appliances having metallic body are connected to earth wire, why ?
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Q13
long answer
5 marks
a) How does rainbow form in the nature ? Explain. Mention the colour of the light that bends the most and that bends the least.
b) How does the eye lens accommodate to see the distant objects and nearby objects ? Explain.
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Q14
mcq
1 mark
The reactants that exchange ions by reacting with each other and form a precipitate among the following are
- A. $\text{BaCl}_2$ and $\text{Na}_2\text{SO}_4$
- B. $\text{Al}_2\text{O}_3$ and $\text{HCl}$
- C. $\text{NaOH}$ and $\text{H}_2\text{SO}_4$
- D. $\text{Na}_2\text{O}$ and $\text{CO}_2$
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Q15
mcq
1 mark
Among $_2X^4$, $_8Y^{16}$, $_{10}Z^{20}$ the elements having zero valency are
[ 2, 8, 10 are atomic numbers of elements ]
- A. $_2X^4$ and $_8Y^{16}$
- B. $_8Y^{16}$ and $_{10}Z^{20}$
- C. $_2X^4$ and $_{10}Z^{20}$
- D. $_2X^4$, $_8Y^{16}$ and $_{10}Z^{20}$
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Q16
short answer
1 mark
The general formula of cycloalkanes is $C_nH_{2n}$ and its first member is cyclopropane ($C_3H_6$). Write the molecular formula and structural arrangement of the fourth member of this homologous series.
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Q17
short answer
1 mark
Packets of chips are flushed with nitrogen gas. Why ?
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Q18
short answer
1 mark
An iron nail is dropped into a test tube having copper sulphate solution. The iron nail gradually turns to brownish colour. Why ?
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Q19
short answer
The resistors $R_1$, $R_2$ and $R_3$ have the values $10 \, \Omega$, $20 \, \Omega$ and $60 \, \Omega$ respectively, which have been parallelly connected to a battery of 24 V in an electric circuit. Then calculate the following: i) The current flowing through each resistor
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Q20
short answer
2 marks
Draw the diagram of arrangement of apparatus to show that acid solution in water conducts electricity and label dilute $HCl$ solution.
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Q21
short answer
2 marks
“Calcium oxide and carbon dioxide are produced on heating calcium carbonate.” Write the balanced chemical equation for this reaction. Mention the type of this chemical reaction.
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Q22
short answer
2 marks
Draw the diagram of arrangement of apparatus to show the action of steam on a metal.
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Q23
long answer
3 marks
a) Depict the formation of magnesium chloride with the help of electron dot structure. b) Hydrogen gas is not liberated when a metal like zinc reacts with nitric acid. Why ? OR How are metals in the middle of the reactivity series extracted from their ores ? Explain.
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Q24
long answer
3 marks
a) Observe the given part of the modern periodic table and answer the following questions : i) Which element is more electropositive ? Why ? ii) Atoms of which element have minimum atomic radius ? Why ? b) Mention the period and group number of the element that has atomic number 19.
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Q25
long answer
3 marks
Name the salts used in the following situations and write their molecular formula : a) To remove permanent hardness of water. b) To make drinking water free from germs. c) To support fractured bones in their right position. OR a) The pH values of four solutions are given in the below table. Classify these into acidic and basic solutions e, f, g, h into acidic and basic solutions : [Table data: e=5, f=13, g=9, h=2] b) Name the antacid used to neutralise excess of acid in the stomach.
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Q26
long answer
4 marks
a) How will ethanol be oxidised ? b) Explain the cleaning action of soaps.
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Q27
mcq
1 mark
“A person immediately starts running soon after observing a snake.” The correct transmission path of reflex impulse in this situation is
- A. Receptor → Sensory neuron → Brain → Relay neuron → Motor neuron → Effector
- B. Receptor → Sensory neuron → Spinal cord → Relay neuron → Motor neuron → Effector
- C. Effector → Spinal cord → Sensory neuron → Relay neuron → Motor neuron → Receptor
- D. Effector → Motor neuron → Relay neuron → Brain → Sensory neuron → Receptor
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Q28
mcq
1 mark
In humans, the testes are located outside the lower abdomen in the scrotum because
- A. to protect testes from mechanical shocks
- B. to increase the production of sperms
- C. to maintain the secretion of testosterone hormone
- D. to maintain the temperature required for sperm production.
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Q29
short answer
1 mark
What is the role of abscisic acid in plants ?
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Q30
short answer
1 mark
Write two examples for the organisms that reproduce by binary fission.
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Q31
short answer
2 marks
Mention the tools used for tracing the evolutionary relationships between the organisms.
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Q33
short answer
The pH values of four solutions are given in the below table. Classify these into acidic and basic solutions :
Solution | pH Value
--- | ---
e | 5
f | 13
g | 9
h | 2
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Q33
short answer
2 marks
Give an example for a food chain of grassland ecosystem. If there is an increase in the number of organisms in the second trophic level, how does this affect on that food chain ?
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Q34
short answer
Name the antacid used to neutralise excess of acid in the stomach.
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Q34
short answer
3 marks
What is pollination ? What are the changes that occur in the flower after pollination ?
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Q35
short answer
3 marks
Coal and petroleum products should be used judiciously. Why ?
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Q36
short answer
1 mark
Explain the cleaning action of soaps.
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Q37
long answer
4 marks
Draw the diagram showing the structure of human brain. Label the following parts :
i) Hypothalamus
ii) Pons.
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Q40
short answer
2 marks
Observe the given figures below. Which figure indicates the massive amount of exchange of gases ? Why ?
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Q41
short answer
2 marks
Observe the given figures below. Name the parts X and Y. What is the function of the part X ?
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Q45
short answer
3 marks
Tall pea plant producing red flowers ($TT RR$) is crossed with short pea plant producing white flowers ($tt rr$). Mention the type of plants produced from these plants in the $F_1$ generation.
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Q46
short answer
3 marks
Tall pea plant producing red flowers ($TT RR$) is crossed with short pea plant producing white flowers ($tt rr$). Write the ratio of plants obtained in the $F_2$ generation by crossing the plants of $F_1$ generation and name the varieties of plants obtained.
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Q47
short answer
3 marks
Analyse the situations given below. Situation 1: The number of green grasshoppers in a green zone has been increasing from one generation to another generation. Situation 2: The number of brown grasshoppers in the same green zone has been reducing. Where could genetic drift be happened more ? Why ?
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Q49
long answer
4 marks
Explain the digestion of food materials in stomach and small intestine.
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Q50
long answer
4 marks
Explain the role of xylem and phloem tissues in the transportation of materials in plants.
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