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Q1
Name the product other than water formed on burning of ethanol in air.
Marks:1
Answer:

Ethanol on burning gives carbon dioxide other than water.

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Q2
How can you show that the magnetic field produced by a given electric current in the wire decreases as the distance from the wire increases?
Marks:1
Answer:

This can be shown by seeing the decrease in the deflection of the needle of the magnetic compass as it is moved away from the current carrying wire.

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Q3
Why does magnesium powder react much more rapidly than magnesium ribbon with dilute sulphuric acid?
Marks:1
Answer:

Out of syllabus.

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Q4
Name the type of fission carried out by Amoeba.
Marks:1
Answer:

Binary fission.

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Q5
Write the expanded form of AIDS.
Marks:1
Answer:

Out of syllabus.

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Q6
An object is placed at a distance of 12 cm in front of a concave mirror. It forms a real image four times larger than the object. Calculate the distance of the image from the mirror.
Marks:2
Answer:

Distance of the object from the mirror (u) = -12 cm
Height of the image /height of the object = h/h’
                                                Given, h/h’ = -4

For mirror,

                                                            h/h’ = -v/u

                                                  Or,        -4 = -v/(-12)

                                                  Or,         v = -12 x 4

                                                  Or,         v = -48

Hence the distance of the image from the mirror = 48 cm in front of the mirror.

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Q7
(i) Draw a diagram to show how two resistors R₁ and R₂ are connected in series.
(ii) In a circuit if the two resistors of 5 ohm and 10 ohm are connected in series, compare the current passing through the two resistors?
Marks:2
Answer:

(i)

(ii) Since the resistors are connected in series the same current is passing through the two resistors.

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Q8
A bulb is rated at 5.0 volt, 100 mA. Calculate its
(i) power and
(ii) resistance.
Marks:2
Answer:

(i) Power (P) = potential difference (V) x current (I)
    P = 5 V x (100/1000) A

                     P = 5 x 0.1

                      P = 0.5 W

(ii) Resistance(R) = V/I

                     R = 5/0.1

                      R = 50 ohm

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Q9
Name the type of nuclear reaction by which the Sun produces its energy. List two conditions which are present at the centre of the Sun responsible for this reaction.
Marks:2
Answer:

Nuclear fusion.
Two conditions which are present at the centre of the Sun responsible for this reaction are as follows:
(i) Millions of degree of temperature.

(ii) A large amount of pressure.

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Q10

Given below are the pH values of four different liquids:
7.0, 14.0, 4.0, 2.0 which of these could be that of

lemon juice,
distilled water,
1 M sodium hydroxide solution,
tomato juice?

Marks:2

Answer:

Since the pH value greater than 7 indicates basic medium, pH equal to 7 is given by neutral medium and a pH value less than 7 indicates acidic medium. Hence