Q1
mcq
1 mark
The SI unit of electric current is
- A. ampere
- B. ohm
- C. volt
- D. watt
Correct Answer: A —
Solution
The SI unit of electric current is Ampere (A). Ohm is the unit of resistance, Volt is the unit of potential difference, and Watt is the unit of power.
Q2
mcq
1 mark
If a ray of light enters from denser medium to a rarer medium obliquely, then the correct statement related to the speed and bending of that light ray in the rarer medium is
- A. speed decreases and bends towards the normal
- B. speed increases and bends away from the normal
- C. speed decreases and bends away from the normal
- D. speed increases and bends towards the normal
Correct Answer: B —
Solution
When light travels from a denser medium to a rarer medium, its speed increases. Due to this increase in speed, the light ray bends away from the normal. Options A and C are incorrect because speed increases, and option D is incorrect because it bends away from, not towards, the normal.
Q3
short answer
1 mark
Write the symbol diagram of the wire crossing without joining used in an electric circuit.
Solution
The symbol for a wire crossing without joining consists of two lines intersecting where one line is drawn with a small loop (or hump) over the other to indicate they are not connected electrically.
Q4
short answer
1 mark
Observe the below figure. When switch is put on, does the Y end of the solenoid repel the S pole of the bar magnet ? Clarify the answer.
Solution
Yes, the Y end of the solenoid will repel the S pole of the bar magnet. By using the Right-Hand Thumb Rule, if the current flows in such a way that the end Y acts as a South Pole, it will repel the S pole of the bar magnet because like poles repel each other.
Q5
short answer
2 marks
Explain the Newton's experiment that shows the recombination of spectrum of white light.
Solution
Isaac Newton showed that white light is composed of seven colors. He placed a second identical glass prism in an inverted position with respect to the first prism. The first prism dispersed the white light into a spectrum. When these colors were passed through the second inverted prism, they recombined to emerge as a beam of white light from the other side of the second prism.
Q6
short answer
2 marks
What is the function of earth wire ? Mention any two precautionary measures to be taken to avoid overloading in domestic electric circuit.
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Q7
short answer
2 marks
$2 \; \Omega$ and $4 \; \Omega$ resistors are connected in parallel in an electric circuit. If $6 \; \Omega$ resistor is used instead of $4 \; \Omega$, then find the difference between the total resistance obtained in both of these arrangements.
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Q8
short answer
3 marks
Draw the ray diagram for the image formation in a concave mirror when the object is placed between ‘C’ and ‘F’. Mention the position and size of the image formed. [ C : Centre of curvature, F : Principal focus ]
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Q9
short answer
3 marks
a) How does rainbow form in the atmosphere ? Explain. b) What is Tyndall effect ? OR What is power of accommodation of the eye ? What is myopia (near-sightedness) ? Mention the causes for this defect.
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Q10
short answer
3 marks
Explain an activity of drawing magnetic field lines around a bar-magnet using a compass needle. OR Explain an experiment to show that ‘a current carrying conductor when kept in the magnetic field experiences a force’.
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Q10
short answer
Explain an activity of drawing magnetic field lines around a bar-magnet using a compass needle.
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Q10
short answer
Explain an experiment to show that ‘a current carrying conductor when kept in the magnetic field experiences a force’.
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Q11
long answer
4 marks
a) An image of an object is formed at a distance of 20 cm from a concave lens of focal length 30 cm. Then find the object distance. b) An object of height 4 cm is placed perpendicular to the principal axis of a convex lens. If the image distance and the object distance are 60 cm and 30 cm respectively, then find the height and magnification of the image.
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Q12
long answer
4 marks
a) State Joule’s law of heating and name any one appliance that works on the heating effect of electricity. b) Give reason : i) The tungsten is used in the filament of electric lamps ii) Copper and aluminium wires are usually used for electricity transmission. OR a) State Ohm’s law. List the factors on which the resistance of a conductor depends. b) “The potential difference between two points of a current carrying conductor is 1V.” Mention the meaning of this statement.
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Q13
mcq
1 mark
An example for the chemical change among the following is
- A. Dissolving of salt in water
- B. Tearing of paper
- C. Rusting of iron
- D. Boiling of water
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Q14
mcq
1 mark
The gas released when metals react with dilute acids is
- A. $H_2$
- B. $CO_2$
- C. $SO_2$
- D. $NO_2$
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Q15
short answer
An image of an object is formed at a distance of 20 cm from a concave lens of focal length 30 cm. Then find the object distance.
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Q15
mcq
1 mark
The difference between molecular formula of two successive compounds in a homologous series is
- A. $C_2H_4$
- B. $CH_4$
- C. $C_2H_2$
- D. $CH_2$
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Q16
short answer
An object of height 4 cm is placed perpendicular to the principal axis of a convex lens. If the image distance and the object distance are 60 cm and 30 cm respectively, then find the height and magnification of the image.
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Q16
short answer
1 mark
The pH values of four solutions P, Q, R and S are 10, 13·7, 7 and 1·2 respectively. Which solution among these can be used to prepare an antacid ? Why ?
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Q17
short answer
State Joule’s law of heating and name any one appliance that works on the heating effect of electricity.
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Q17
short answer
1 mark
“Aluminium articles do not corrode easily like iron articles.” Justify this statement.
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Q18
short answer
Give reason :
i) The tungsten is used in the filament of electric lamps
ii) Copper and aluminium wires are usually used for electricity transmission.
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Q18
short answer
1 mark
Compound X reacts with concentrated sulphuric acid to produce compounds Y and Z. If Y is the first member of alkene, identify the compound X.
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Q19
short answer
State Ohm’s law. List the factors on which the resistance of a conductor depends.
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Q19
short answer
2 marks
Acid rain water conducts electric current but distilled water does not. Why ?
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Q20
short answer
“The potential difference between two points of a current carrying conductor is 1V.” Mention the meaning of this statement.
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Q20
short answer
2 marks
Write the differences between calcination and roasting.
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Q20
short answer
2 marks
Explain the formation of ionic bond between sodium and chlorine atoms.
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Q21
short answer
2 marks
Write the molecular formula and structure of the following carbon compounds :
i) Cyclopentane
ii) Propanol.
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Q22
short answer
3 marks
Draw the diagram of the arrangement of apparatus used to show the action of steam on a metal. Label the following parts :
i) Glass wool soaked in water
ii) Delivery tube.
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Q23
short answer
3 marks
Write the molecular formula and two uses of each of the following compounds :
i) Baking soda
ii) Plaster of Paris.
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Q23
short answer
3 marks
Name the products of chlor-alkali process. Write one use of each.
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Q24
short answer
3 marks
Balance the following chemical equations :
i) $N_2 + H_2 \rightarrow NH_3$
ii) $H_2O \rightarrow H_2 + O_2$
iii) $MnO_2 + HCl \rightarrow MnCl_2 + H_2O + Cl_2$
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Q26
mcq
1 mark
The structural and functional unit of kidney is
- A. Neuron
- B. Nephron
- C. Cyton
- D. Muscle cell
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Q27
mcq
1 mark
A common bacterial infection that spreads through sexual contact in human beings is
- A. Gonorrhoea
- B. AIDS
- C. Hepatitis-B
- D. Genital warts
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Q28
mcq
1 mark
In a zygote there are 23 pairs of chromosomes. Then, the number of chromosomes present in the normal cell of parent organism is
- A. 24 pairs
- B. 23 pairs
- C. 46 pairs
- D. 12 pairs
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Q29
short answer
1 mark
The extract of blood report that shows the haemoglobin content of three individuals is given in the table below:
Persons: A (11.1), B (12.0), C (13.3)
Based on this report, which person’s body will receive more oxygen ?
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Q30
short answer
1 mark
While studying the growth of a seedling, the seedling is kept as shown in the figure. What type of tropism is shown by the part labelled as ‘X’? Why?
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Q31
short answer
1 mark
Observe the figures of flower A and B given below. Which flower undergoes only cross pollination? Justify your answer.
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Q32
short answer
2 marks
How does adrenaline hormone help an athlete to prepare for running?
OR
How do auxins promote the growth of tendrils of a climber plant around a support?
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Q33
short answer
2 marks
Draw the diagram showing the structure of open stomata and label the following parts:
i) Guard cells
ii) Chloroplast
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Q34
long answer
3 marks
Write the differences between biodegradable and non-biodegradable substances with an example.
OR
Construct a food chain by using the organisms: snake, frog, grass and grasshopper. Which organism has more accumulation of harmful chemicals in this food chain? Why?
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Q35
short answer
Carbon atoms do not form $C^{-4}$ anion or $C^{+4}$ cation. Why ?
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Q35
long answer
3 marks
Yellow seed producing (YY) pea plant is crossed with green seed producing (yy) pea plant. Show the results obtained in $F_2$ generation with the help of checker board. Mention the phenotypic and genotypic ratio of the plants produced here.
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Q36
short answer
Write any two differences between saturated and unsaturated hydrocarbons.
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Q36
long answer
3 marks
Draw the diagram showing the structure of human brain. Label the following parts:
i) Cerebrum
ii) Pons.
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Q37
long answer
4 marks
a) What is the role of following enzymes in the human digestive canal?
i) Trypsin
ii) Amylase
iii) Lipase.
b) What is transpiration?
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Q38
short answer
Which salts are responsible for hardness of water ? The detergents are effective even in hard water. Why ?
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Q38
long answer
5 marks
a) List the functions of the vas deferens and prostate gland in the human male reproductive system.
b) What are the changes that occur in a flower after the fertilization?
OR
a) How are reproductive processes different in Hydra and Planaria? Explain.
b) How does the uterus prepare to receive a fertilized egg in women? What happens if the egg is not fertilized? Explain.
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