SECTION-A
1 The magnetic field in each region is uniform. Draw a diagram to represent it.
2 All information for our environment is detected by specialised tips of some nerve cells mention the name given to such tips and mention where are they located.
3 A black surface absorbs more heat radiations as compared to a white or a reflecting surface under identical conditions. List two solar devices which make use of this property in their design.
4 (i) When a metal ‘X’ is added to salt solution of a metal ‘Y’, following chemical reaction takes place: Metal X + salt solution of ‘Y’ --→salt solution of ‘X’ ‘+’ metal ‘Y’
(ii) Mention the inference you draw regarding the reactivity of metal ‘X’ and ‘Y’ and about the type of reaction. State the reason of your conclusions.
5 Draw a schematic circuit diagram for a circuit in which three resistors R1, R2, and R3 a plug key under closed condition, an ammeter is joined in series with a 5V battery. Also, a voltmeter is connected to measure the potential difference across the resistor R1.
7 In the following chemical reaction “zinc oxide reacts with carbon to produce zinc metal and carbon monoxide”. ZnO+C →Zn+CO
(i) Identify the substance getting oxidised and the one getting reduced.
(ii) State the reason for choosing the substances in (i).
(iii) Name the type of reaction and give another example of similar type of reaction.
OR
Thermal decomposition of lead nitrate results in the emission of brown fumes and a residue is left behind when the activity gets over.
(i) State the reaction that takes place in the above-mentioned activity in the form of a balanced chemical equation.
(ii) Identify the brown fumes and residue giving their chemical names.
8 In a thermit reaction, a compound of iron reacts with a metal.
(i) Name the metal used in this reaction.
(ii) After completion of this reaction a metal is obtained in the molten state. Identify the metal.
(iii) Represent this reaction in the form of a balanced chemical equation.
(iv) Mention the most common use of this reaction.
9 Sugandha prepares HCl gas in her school laboratory using certain chemicals. She puts both dry and wet blue litmus papers in contact with the gas.
(i) Name the reagents used by Sugandha to prepare HCl gas.
(ii) State the colour changes observed with the dry and wet blue litmus paper.
(iii) Show the formation of ions when HCl gas combines with water.
10 We have a piece of copper wire of resistance R. This wire is drawn out so that its length is doubled. Find the new resistance of the wire in terms of its original resistance.
Two identical wires one of nichrome and other of copper are connected in series and a current
(I) is passed through them. State the change observed in the temperatures of the two wires. Justify your answer. State the law which explains the above observation.
11 You are given a strong bar magnet and a magnet compass needle. Describe an activity by which the magnetic field lines due to the bar magnet can be drawn.
OR
(a) Why is tungsten used for making bulb filaments of incandescent lamps.
(b) Name any two electric devices based on heating effect of electric current.
(c) An electric bulb is connected to a 220V generator. The current is 2.5 A. Calculate the power of the bulb.
12. Mention the role of following in digestion -
(i) pepsin (ii) Saliva (iii) Villi
13 Electrical impulses are an excellent means of quick transfer of information in animals but there are limitations to the use of electrical impulses List such two limitations. State the other means of communication used by most multicultural organisms between the cells?
14 A gland secretes a particular hormone. The deficiency of this hormone in the body causes a particular disease in which the blood sugar level rises.
(i) Name the gland and the hormone secreted by it.
(ii) Mention the role played by this hormone.
(iii) Name the disease caused due to deficiency of this hormone.
15 It has been observed that the construction of big dams have certain problems associated with them. List three problems.
Please click the link below to download the full pdf file for CBSE Class 10 Science Sample Paper Set I
