जिल्हा परिषद माध्यमिक विद्यालय, विडूळ ता . उमरखेड जि. यवतमाळ
Online Exam
Class - 10 th , Sub :- Science and Technology Part - I, Marks - 40, Time - 2 Hours
Date - 30 / 03 / 2021 , Timing - 12 : 00 to 2 : 00
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Q.1. (A) Choose the correct option: [5]
i. Working of calorimeter based upon ------------------------.
(a) percentage relative humidity
(b) anomalous behaviour of water
(c) principle of heat exchange
(d) dew point temperature
ii. Aluminium Oxide is -------------------- in nature.
(a) acidic
(b) basic
(c) amphoteric
(d) neutral
iii. Mirage is the effect of atmospheric --------------on a small scale.
(a) scattering
(b) dispersion
(c) reflection
(d) refraction .
iv. We can see the sun even when it is little below the horizon because of -------------
(a) absorption of light
(b) dispersion of light
(c) refraction of light
(d) reflection of light
v. When rays of light are incident on a glass slab, then the incident ray and emergent ray ----------------------- to each other .
(a) concurrent
(b) opposite
(c) perpendicular
(d) parallel
(B) Solve the following sub-questions: [5]
i. State true or false:
Higher the temperature of air , lower is the amount of water vapour needed to saturate it.
ii. Write the correlated answer:
Reflection of light : Mirror :: -------------------- : Prism
iii. Find odd man out:
Galvanization , Anodization , Roasting , Electroplating.
iv. Name two allotropes of Carbon .
v. Name the following ;
The oxide that forms salt and water by reaching with both acid and base.
Q.2. (A) Give scientific reasons (any two): [4]
i. The bottom of a pond appears raised.
ii. Anodes need to be replaced from time to time during electrolysis of Alumina.
iii. Planets do not twinkle.
(B) Answer the following questions (any three): [6]
i. What is regelation ? why is it observed ?
ii. Identify acidic and basic oxides from the following Na2O, SO2 , MgO , CO2 .
iii. A teacher was explaining the phenomena of advanced sunrise and delayed Sunset , what reason should the teacher give for the phenomena?
iv. Explain with an example the effect of atmospheric refraction on a small scale.
v. Distiguish between , Calcination and roasting.
Q. 3. Answer the following Questions .(any Five ) (15)
i. Figure shows the experiment of dispersion of sunlight , write in brief the observation you made and conclusion by filling the boxes given in figure.
ii. Based on the below diagram , answer the following question.
a) What do labels A and B denote ?
b) What do labels C and D denote ?
c) What does the above diagram represent ?
iii. Explain Hall’s process used for concentration of Bauxite ore.
iv. Explain thermit reaction and give its uses.
v. Explain how fishes can survive in extreme winter , when ponds and lakes are frozen. b) give one example where anomalous behavior of water proves disadvantageous.
vi. A copper sphere of 100g mass is heated to raise its temperature to 10000c and is released in water of mass 195 g and temperature 200c in a copper calorimeter. If the mass of calorimeter is 50 g , what will be the maximum temperature of water ? ( given, specific heat of copper = 0.1 cal/g0c and specific heat of calorimeter = 0.1 cal/g0c )
vii. State and expalin Laws of refraction of light.
viii. The electronic configuration of metal ‘A’ is 2,8,1 and that of metal ‘ B’ is 2,8,2 . which of the two metals is more reactive ? Write their reactions with dilute hydrochloric acid .
Q. 4. Answer the following . (any one) (05)
i. Label the following diagram which shows reaction of a metal with water and answer the following questions.
a) Name two metals which do not react in the above experiment .
b) What are the properties of the gas produced in the above experiment?
c) Which metal should be used in the above experiment?
ii. Heat exchanged between two objects A and B is studied
a) if temperature of object A starts rising , which of the two objects is cold?
b) Label ‘c’
c) What is special property should be associated with ‘C’
d) How will temperature of object B change?
e) State the relation of heat exchange for given situation.
