Physical Science Question Paper (Class X)

                         Group A 

1. MCQ type question ( All questions are compulsory ) : 

( https://forms.gle/ePqysL8Ab8CzDk3S6 )

 Each of the following questions has four alternatives . Write the correct one . 

1.1 Which one of the following does not deplete ozone layer ? 

a) NO          b) N₂O   c) CO₂    d) CFC 

1.2 Which  of the following is equal to 290K ? 

a) 30ºC   b) 17ºC  c) 0ºC  d) 27ºC 

1.3 The molecular weight of methene is 16 , which of the following is its vapour density ? 

a) 22.4   b)  8     c) 16     d) 32 

1.4 Which of the following has the highest thermal conductivity  in cal.cm⁻¹s⁻¹K⁻¹ unit ) ? 

a) Copper    b) Gold  c) Iron   d) Diamond 

1.5 For which angle of incidence deviation is minimum during refraction of light from lighter to denser medium ? 

a) 60º  b) 0º   c) 90º  d) 45º  

1.6 Which pair of the following is the two terminal colours in pure spectrum of while light ? 

a) Red and violet   b) Red and green   c) Violet and orange   d) Blue and indigo 

1.7 Which one of the following is the unit of electric charge ? 

a) volt   b) coulomb   c) ohm    d) watt 

1.8 What will be the equivalent resistance where two resistances of 3 ohm and 6 ohm are connected in parallel combination ?
a) 3 ohm  b) 4 ohm   c) 2 ohm  d) 1 ohm 

1.9 Which of the following is the correct order of decreasing power of ionising of gas ?

a) α >β ＞४  b) ४ ＞ β ＞ ∝  c)  α ＞४ > β   d) ४ > α > β 

1.10  Which of the following is not a transition element ? 

a) Fe   b) Co  c) Ca  d) Cr 

1.11 Which one of the following is an ionic compound ? 

a) HCl    b) CH₄   c) MgCl₂  d) NH₃ 

1.12 Which of the following is a weak electrolyte ? 

a) CuSO₄   b) KOH  c) H₂SO₄  d) CH₃COOH 

1.13 Which of the following gases can be prepared by Kipp's apparatus ? 

a) N₂   b) H₂S      c) HCl  d)  NH₃ 

1.14 Hematite is the one ore of which of the following metals ? 

a) Copper  b) Aluminium   c) Iron  d) Zinc  

1.15 Which of the following functional groups is present in ethyl alcohol ? 

a) 一CHO   b) ＞C=O    c) 一COOH    d) 一OH 

                        Group -  B 

2. Answer the following questions(Alternative are to be noted ) 1 x 21 =21 

2.1 In which layer of atmosphere do storm and rains occur ?

Or 

What are the bacteria called which decompose biomass to methane in biogas plant ? 

2.2 Fill up the blank : In stratosphere temperature .............................with increase in altitude .

2.3 What is the temperature in ºC at which volume of a gas will be zero at constant pressure according to Charles' law ? 

2.4 A gas at fixed temperature is kept in a closed vessel . Some more amount of the same gas is added to the vessel without altering the temperature .What will be the change in pressure ? 

2.5 What is the SI unit of coefficient of linear expansion of a solid ? 

            or 

Write down the relation among the linear , surface and volume expansion  coefficients of a solid ? 

2.6 What type of spherical mirror is used in the head light of cars ? 

2.7 Where will the image be formed when an object is placed at the focus of a convex lens ? 

2.8 Define the resistance of a conductor according to Ohm's law .

2.9 What is the SI unit of resistivity ?

2.10 From which part of an atom the radioactive rays emanate ?

     or 

Name a positively charged radioactive particle . 

2.11 Match the right column with the left : 

Left Column	Right Column
2.11.1 The most electronegative element of group 17	i ) Zn
2.11.2 An alkaline earth metal	ii) Sn
2.11.3 A metal which can be prepared by the carbon reduction of its oxide .	iii) F
2.11.4 Present in bronze	iv) Mg

2.12 Which type of electricity is used in electrolysis ? 

2.13 What is used as electrolyte in the electroplating of gold over silver ? 

2.14 Write the formula of the precipitate when an aqueous solution of ammonia is added to the aqueous solution of ferric chloride ? 

      or 

What is liquor ammonia ? 

2.15 What change of colour is observer when a few drops of aqueous  solution of sodium nitroprusside is added to an aqueous solution of hydrogen sulphide made alkaline with NaOH solution ? 

2.16 Write whether the following statement is true or false : 

aqueous solution of glucose can conduct electricity .

2.17 write UPAC name of the following compound . 

CH₃CH₂CHO 

2.18 Which gas is liberated when Na HCO₃ is added to acetic acid ? 

      or 

Write down the formula of the organic compound produced in the first step in the substitution reaction of methane with chlorine . 

Group - C 

3. Answer the following questions ( Alternative to be noted ) : 2x 9 = 18 

3.1 Write the two harmful effects of depletion of ozone layer on human health and environment .

3.2 The volume of a gas at 300 K temperature and 760mmHg of pressure is 300 cm³ . What is the volume of the gas at STP ?

 Or 

Find out the volume of 2.2 g of CO₂ at temperature 300K and 570mmHg 0f pressure ( C = 12 , O = 16 , R = 0.082 Latmos .K⁻¹ mol⁻¹ ) 

3.3 Write the laws  of refraction of light .

3.4 How does resistance depend of length and cross section of  a conductor / ? 

Or 

Write down Fleming's left hand rule .

3.5 Draw Lewis -dot diagram of  carbon dioxide .

Or 

Show with an example that ionic can be formed even when its ions have no filled octet .

3.6 Compare two properties of ionic and co-valent compounds 

3.7 Write the condition and balanced chemical equation of the reaction for the preparation of ammonia gas in the laboratory. 

 Or 

Show that H₂S is  a reducing agent with the help of a chemical reaction .

3.8 Write with example the difference between mineral and ore .

3.9 Write the names of monomers of PVC an teflon .

Or 

 Write constitutional formulas of two organic compounds having the same molecular formula C₂H₆O 

          Group -D 

4. Answer the following questions ( Alternative are to be noted ): 3x 12 =36 

4.1 Establish the combined form of Charles' law and Boyle's law. 

4.2  How many gram of ferrous sulphide will be required to prepare 1.7 gram of hydrogen sulphide  gas by the reaction of ferrus sulphide and dilute sulfuric acid ? ( Fe =56 , S = 32 , H = 1 )  

Or 

Metallic zinc and carbon monoxide are produced when zinc oxide is heated with carbon . How many gram of carbon will be required to produce 31.785 g of zinc and 14.000 g of carbon monoxide from 40.685 g of zinc oxide ? How many mole of carbon monoxide is produced in the reaction ? (C = 12 , O =16 ) 

4.3  What is meant by coefficient of thermal conductivity of a substance ? Establish the relation between CGS and SI units of it . 

4.4 What is meant by focus of  a lens ? 

4.5 Prove that  δ = i₁  + i₂ - A in case of refraction of light through a prism. (The symbols has usual meaning ) 

  Or  

If the refractive index of a medium for red and violet light are μ₁ & μ₂ respectively prove that μ₁ < μ₂ 

4.6 State Joule's law of heating of current . 

4.7 When an electric lamp is connected to 220V mains  1 ampere of current flows . What will be the current when the lamp is connected to 110V mains ? 

 Or 

Find the ration of the resistances of two lamps of 220V- 60W and 110V- 60W . 

4.8 What is radioactivity ? 

Write down  two uses of radioactivity . 

Or 

When a radioactive atom emits an α particle how are atomic number and mass number changed in the daughter atom ? 

By the emission of which radioactive ray from a radioactive atom , the atomic number remains unchanged ? 

4.9 What is meant by ionization energy of an element ? 

Arrange Li , Na and K in the increasing order of their ionization energy . 

4.10 Mention the following points in case of electrorefining of copper . 

i) electrodes  used and the electrolyte 

ii) the chemical reaction occurring at the electrodes .

4.11 In the laboratory preparation of nitrogen , why instead of heating directly a concentrated aqueous solution of ammonium nitrite , a mixed aqueous concentrated solution of ammonium chloride and sodium nitrite mixed in equimolar proportion is heated ? Answer with balanced chemical equations . 

Or 

Write with condition and balanced chemical equation how urea is industrially prepared . 

4.12 C₂H₆ is called a saturated hydrocarbon , but why is C₂H₄ called an unsaturated hydrocarbon ? 

Or 

How will you convert HC≡CH → Br₂CHCHBr₂ ? 

Mention  one use of CNG 

Answer keys : 

    Q 1 . To know answer copy the following link and paste it on your browser and take part  in the quiz online .

    Q2 . 1) Troposphere or Methanogens 2) decrease 3) -273 ºC 4) pressure will increase 5) K⁻¹ Or α =β/2 =४/3  6) concave mirror 7) at infinite distance 8) R =V/I , ratio of potential difference and current is resistance . 9) Ohm.metre 10) nucleus  11) 1. → iii) F  2. → iv) Mg  3.  →i) Zn  4. → ii) Sn  12) direct current (D.C) 13) K[Au(CN)₂] 14) FeCl₃ +3 NH₄(OH) → Fe(OH)₃↓ +  3NH₄Cl  Or aqueous solution of ammonia ( NH₄OH ) 15) purple colour  16) False 17) 1-propanal 18) CO₂ or CH₃Cl 

Q3 .

 3.1) Two harmful effects of  depletion of ozone layer a) Ultra violet rays directly reach earth surface and causes skin cancer b) UV radiation hinders the growth of plants .

3.2) Here pressure is constant . Initial temperature T₁ = 300K ,initial volume V₁ = 300 cm³ final temperature T₂ = 0ºC = 273K , final volume V₂ = ? . From Charle' law  V₁/T₁ = V₂ /T₂ 

⇒ 300/300 = V₂/273  Or , V₂ = 273  cm³ 

Or Molecular weight of CO₂ = 12 + 2x16 = 44 , 2.2 g of CO₂ = 2.2/44 = 0.05 mole  . From PV =n RT we get 570/760 V = 0.05 x 0.082x 300 ⇒ V = 760 x 0.05 x 0.082 x 300/570 = 1.64 L

3.3) Laws of refraction : a) The incidence ray , the refracted ray and normal at  the incident point all lie in the same  plane .

b) The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for a pair of two given media and for a particular colour of light . This constant is called the refractive index of the second medium with respect to the first medium .

1​

₁μ₂ = sin i/sin r 

3.4) Resistance is proportional to the length of conductor and inversely proportional to the cross-sectional area of conductor .

Or 

Fleming's left hand rule : 

If we arrange our thumb , forefinger and middle finger of the left hand perpendicular to each other , then the thumb points towards the direction of the force experienced by the conductor , the forefinger points towards the direction of the magnetic field and the middle finger points towards the direction of the electric current .

3.5) 

Or 

CuO is an ionic compound . Cu²⁺ has no filled octet as Cu has 29 electrons. 1s22s22p63s23p64s23d9 is the electron configuration of copper .  Cu²⁺ has electron configurations1s22s22p63s23p64s23d9 = [Ar]3d⁹ But O²⁻ has filled octet. 1s22s22p6 is  the electron configuration of  O²⁻ .

3.6) Comparison between ionic and covalent compound :

Ionic compound	Co-valent compound
1. Occurs during transfer of electrons from one atom to another	1. Occurs when two atoms share their valency electrons
2. Higher melting point	2. Lower melting point

3.7) Balanced equation for ammonia preparation in laboratory :

                                heat 

2NH₄Cl  + Ca(OH)₂ = CaCl₂ + 2H₂O +2NH₃(g) 

Or 

2FeCl₃ +H₂S →2 FeCl₂ + 2HCl + S 

Here H₂S reduces FeCl₃ to FeCl₂ , Hence it acts as reducing agent . 

3.8) 

Mineral	Ore
1. Minarals are the natural inorganic substance that exist in earth crust .	1.Ores are the minarals from which metal can be extracted  economically and conveniently .
2. All minerals  are not ores .	2. All ores are minerals .
3.example ; Clay is the mineral of Aluminium	3. Example : Bauxite and Cryolite are ores of Aluminium
4.Minerals may or may not contain a good percentage of metals	4. Ore always contains a good percentage of metal

3.9 )

Monomer of PVC 

 CH₂ = CHCl vinyl chloride

Monomer of teflon 

CF₂ = CF₂ tetrafluoroethylene.

Or 

C₂H₅OH - Ethanool   and CH₃O CH₃ - dimethayl ether 

Environment & Science (class VI questions)

 1.a) Match the column :

Column A	Column B
Igneous Rock	Lime Stone
Sedimentary Rock	Granite
Metamorphic Rock	Slate

b) Name two fossil fuels . 

2. Fill up the gaps with the following words : 

( breath , gram , 100, second ) 

a) Area = Length x -------------.

b) Unit of mass is --------------.

c) Unit of time -----------.

d) 1 km = ----------------dam 

3.a) Identify the work as pull or push 

i) Withdrawing water from well 

ii) Opening the Zip of a bag 

b) Name one force which is acting without touch .

4. i) Fill up the blank spaces : 

a) Pressure = --------/ Area 

b) SI unit of pressure is  -----------------------

c) The pressure of a fluid depends on ----------.

ii) State True or False 

a) When we blow heavily between two pages , the pressure of moving air decreases . 

b) Fluid means only gaseous substance .  

Answer : 

1. a) Igneous rock → Granite , Sedimentary Rock → Lime Stone , Metamorphic Rock → Slate 

b) Petrolium , coal 

2. a) breath b) gram c) second d) 100 

3. a) i) pull ii) pull/ push  b) gravitational force  

4. i) a) Force b) Newton/metre² c) depth  ii) a) True b) False 

Environment & Science (Class VII ) some questions

 1.Choose the correct answer:

Environment & science (class VIII) Some questions

 1. Fill up the gaps with following words 

( Liquid, decreases, calorie, melting, mass)

i) The amount of heat required for increasing the temperature of a body depends on ............

ii) The unit of heat is ...............

iii) The change of state from solid to ..........is called  -------.

iv) If the pressure decreases the boiling point of a liquid _-------------.

2. 

a) Write the name of a substance that is non conductor of electricity . 

b) What is the name of the electrode that is connected to the positive end of of the battery ?

c) What is the name of the electrode that is connected to the negative end of the battery ? 

d) Which material would you use for gold plating of a metal at the anode and at the cathode ? 

3. Answer the following .

a) 2 H₂O₂ = 2H₂O + O₂ , Name the catalyst of the reaction . 

b) During exothermic reaction , the energy is ------------.

c) During oxidation -----------------reacts with a compound .

d) Identify the oxidation & reduction reaction 

i) Fe³⁺ +e = Fe²⁺ 

ii) Cl⁻ = Cl + e 

Answer : 

1. i) mass ii) calorie iii) liquid , melting iv) decreases 

2.a) plastic , wood ,glass etc  b) Anode c) Cathode d) The material on which gold is to be coated is used as cathode and gold is used as anode .

3. a) manganese dioxide ( MnO₂ ) b) released c) oxygen  d) i) reduction ( electron is accepted) ii) oxidation ( electron released ) 

Second Summative Examination -2022(Physical Science ,class -X )

 Group - A 

1. Chose the correct answers :  1x7 = 7 

a) What will be the volume of 3.2 g of oxygen at S.T.P .

i) 22.4 L  ii) 2.24 L   iii) 0.224 L  iv) 0.0224 L 

b) The co-efficient of linear expansion of solid depends only on the unit of 

i) Length ii) Area   iii) Temperature iv) None of those 

c) Unit of resistance is 

i) Ampere  ii)  Ohm   iii) Coulomb  iv) Joule 

d) Which one is not conductor of electricity 

i) Copper ii) Gold  iii) Aluminium  iv) Plastic 

e) Which of the following compounds does not conduct electricity ?

i) Starch ii) Vinegar   iii) Table salt iv ) Baking soda 

f) Which of the following is used to dry moist ammonia ? 

i) Conc. H₂SO₄     ii)     P₂O₅  iii) CaO   iv) CaCl₂ 

g) Which of the followings is an ore of Aluminium ? 

i) Bauxite  ii) Haematite iii) Malachite  iv) Chalcopyrite 

Ans  : a) ii) 2.24 L  b) iii) Temperature c) ii) Ohm  d) iv) Plastic e) i) Starch f) iii) CaO g) i) Bauxite 

Group -B 

2.Very short answer type questions: 1x9 =9 

a) CaO and CO₂ are produced on heating of CaCO₃ .( T or F)

b) S.I unit of thermal conductivity is _------------.

c) Write down the relation between ∝ ,β ,४ for a solid .

d) S.I unit of charge is _--------------.

e) Resistance of a conductor indirectly proportional to the length of the conductor.(True or False)

f) The electrode connected to positive terminal of battery is called cathode .(True or False)

g) Pure water _--------- conductor of electricity.

OR 

Which ion migrates towards the cathode during the electrolysis of aqueous solution of CuSO₄ using copper electrodes ?

h) Write down the formula of black precipitate when H₂S gas is passed through an aqueous solution of lead nitrate . 

i) Write down the balanced chemical reaction for extraction of Fe from Fe₂O₃ by Thermite process.

Answer:

a) T b) Watt.m⁻¹K⁻¹  c) α =β/2 = ४/3 d)Coulomb  e);False  f) False   g) very poor  Or Cu⁺²  h) PbS.  i) Fe₂O₃ + 2Al = Al₂O₃ + 2Fe + heat 

Group -C 

3. Short Answer type Questions. 

a) How does the resistance of a semiconductor change with increase of temperature.What is the unit of specific resistance or resistivity ?

b) Write the reaction of ammonia preparation by Haber's process mentioning the condition of reaction.

c) Arrange in order of increasing carbon content in wrought iron, cast iron and steel .

Ans : 

a) Resistance of semiconductor decreases with increase of temperature . Unit of specific resistance is Ohm.m .

b) N₂ + 3H₂ → 2NH₃

Condition of reaction - At 200 Atmospheric pressure and 400-450 ⁰C with iron catalyst nitrogen and hydrogen react to produce ammonia.

c) Order of carbon content of different iron : wrought iron<Steel <cast iron 

Group-D 

4.Long answer type questions:

a) On strong heating of limestone (CaCO₃) decomposes into quicklime and CO₂ . How much quantity of quicklime will be produced on complete decomposition of 30 g of limestone by the above reaction ? 

b) What is the Thermal conductivity ? What is its units in SI system ? Write the expression for the thermal conductivity explaining the meaning of each term .

c) State Ohm's law .If the potential difference between two ends of a conductor be 15 volt for which current flowing through is 3 ampere .Find the resistance of the conductor.

d) Write the expression for the equivalent resistance for series combination of two resistances r₁ and r₂ .If the resistance of two coils of wire are 3 Ω &6 Ω.What will be the equivalent resistance ?

Or 

Write the Joule's law of heating effect of current with mathematical expression. 

e) Write down the cathode and anode reaction for the electrolysis of acidified water using platinum electrode.Which materials are used on anode and cathode during electro refining of impure copper .

f) Write down the balanced chemical reactions for the industrial manufacture of SO₃ from SO₂ by contact process .How is H₂SO₄ prepared from SO₃ produced ?

  Ans: 

a) CaCO₃  = CaO + CO₂ 

Molecular weight of  calcium carbonate (CaCO₃ ) [ Ca = 40 ,C = 12 , O = 16]

= 40 + 12 + 16 x 3 = 40 + 12 + 48 = 100 and molecular weight of  CaO = 40 + 16 = 56 .

From the above reaction we get 56 g of quicklime( CaO )from 100 g of limestone( CaCO₃) 

So from 30 g . of limestone we get 56/100 x 30 = 16.8 g of quicklime .

b) Thermal conductivity is the rate of flow of heat energy per unit area at unit temperature gradient .

Its SI unit is Watt. m⁻¹ K⁻¹ .

Expression of thermal conductivity ; 

Q/t = - k A( T₁ - T₂) /L  = k A( T₂ - T₁ ) /L 

Here" k"  is thermal conductivity , T₂ > T₁  (T₂ ,  T₁ are temperature in hot and cold surface respectively ) 

Q/t = heat flow per unit time .A = area of surface through which heat is conducting .

c) Ohm's law :

Electrical Current flowing through a conductor is directly proportional to potential difference across the two ends of the conductor provided Temperature and other physical conditions remain constant .

If the potential difference between two ends is V and current flowing is I then according to Ohm's law , V ∝ I 

⇒V = R I (R = proportionality constant)

R is known as resistance of conductor.

This is mathematical expression of Ohm's law

 Here V = 15 Volt I = 3 amperes 

Hence from the above relation we get ,

15 = R X3 

∴ R = 15/3 = 5 Ohm .

Therefore resistance of the conductor is 15 Ω

d) 

Equivalent resistance for Series combination of two resistance r₁ 

and r₂ is R = r₁ + r₂ 

Here two resistances are 3 ohm and 6 ohm 

So equivalent resistance is R = 3 + 6 = 9 ohm.

Or 

Joule's law forheating effect of current .

1) If resistance(R) and time(t) remain constant then heat(H) generated due to current(I) is directly proportional to the square of current.

i.e H ∝ I² ( R, t = constant.)

2) Heat generated Is proportional to resistance when current and time remain constant.

i.e H ∝ R ( I, t = constant.)

3) Heat produced due flow of current is proportional to time of flow when resistance and current remain constant.

ie H ∝ t ( I,R = constant.)

Combining the above three equations we get ,

H ∝ I² Rt 

⇒ H = I²Rt (S I system)

e) Electrolysis of acidified water using platinum electrodes:

Water is ionised as 

H₂O → H⁺ + OH⁻

Cathode reaction:

2H⁺ +2e = 2H 

2H = H₂ 个

Anode reaction:

4OH⁻ -4e = 4H₂O + O₂个

So we get hydrogen gas from cathode and oxygen from anode .

For electro refining of impure copper a slab of impure copper is used as anode and a thin strip of pure copper is used as cathode.

f) 2SO₂+ O₂ → 2SO₃ 

(Conditions of reaction , temperature needed 400-450ªC, Catalyst V₂ O₅ ,pressure - 1- 2atm.

In order to produce sulphuric acid in contact process supher trioxide is absorbed in concentrated sulphuric acid to form oleum or fuming sulphuric acid . Next with oleum water is added to produce sulphuric acid .

H₂SO₄ + SO₃ →H₂S₂O₇(oleum)

H₂S₂O₇ + H₂O →2H₂SO₄