10 Science Solved Sample Paper 4

10 Science Solved Sample Paper 4 – Page 5

Section E

Question: 22. The reading of current flowing through a conductor and the potential different across its two ends are shown in the ammeter and voltmeter given below. What will be the value of resistance in it? (2 marks)

Answer:

I = 400 m.A;     I = 400/1000 A;    V = 8 Volts.
R = V/1 = 8 × 1000/400 = 20 Ω    ⇒   R = 20 Ω

Question: 23. Two resistances R₁ = 10 ohm and R₂ = 10 ohm are to be connected with 20 V battery. Out of which of the following maximum current will flow. Calculate its magnitude. [2]

Answer: Same current will flow through all the circuits, As resistors are connected in series in all the three circuits.

R = 10 + 10 ⇒ 20 ohms;         V = 20 Volts;        I = ?

I = V/R = 20/20 = 1 A (Ampere);        I = One Ampere.

Question: 24. Match the important chemical given in column (A) with the chemical formulae given in column (B).

Answer:

Question: 25. Draw the diagram of a germinated dicot seed and label on it the following: [2]
Cotyledon, Plumule

Question: 26. If 2 ml of dilute acetic acid is added to a test tube containing powdered sodium bicarbonate, what will you observe? Write a balanced chemical equation of the reaction taking place and also the chemical name of the salt formed. [2]

Answer:

1. A colourless gas with beisk effervescence will evolve.
2. Ch₃CHOOH + NaHCO₃ → CH₃COONa + CO₂ + H₂
3. Sodium Acetate

Or
What do you observe when you drop a few drops of acetic acid into a test tube containing:
(1). Phenophthalein
(2). Universal indicator
(3). Distilled water
(4). Sodium hydrogen carbonate

Question: 27. An object is placed at a distance of 45 cm from a convex lens of focal length 18 cm. Draw a ray diagram to show the nature, position and size of image formed. State how the position and size of the image would change if the object is moved towards the lens and is kept at a distance of 34 cm from it.

Hints:

1. If object is 34 cm from the lens, then the object position will be between F and 2F.
2. Image will now be formed beyond 2F.
3. It will be larger in size than the object.

Or
Draw a path of light ray passing through a prism. Label angle of incidence and angle of deviation in the ray diagram.