If 104 g of water at 30 ° C is taken in a calorimeter made of copper of mass 42 g . When a certain mass of ice at 0 ° C is added to it, the final steady temperature of the mixture after the ice has melted, was found to be 10 ° C . Find the mass of ice added. (Specific heat capacity of water = 4 . 2 J g - 1 ° C - 1 , Specific latent heat of fusion of ice = 336 J g - 1 , Specific heat capacity of copper = 0 . 4 J g - 1 ° C - 1 )

Data Given, Mass of water m 1 = 104 g , temperature of water T 1 = 30 ° C , final temperature T 2 = 10 ° C , mass of calorimeter m 2 = 42 g , temperature of ice T 3 = 0 ° C , specific heat capacity of water S w = 4 . 2 J g - 1 ° C - 1 , specific latent heat of fusion of ice L = 336 J g - 1 , specific heat capacity of copper S c = 0 . 4 J g - 1 ° C - 1 . Let the mass of ice added be m = x , According to the principle of calorimetry, total heat energy lost is equal to total heat gain. ⇒ m 1 S w T 1 - T 2 + m 2 S c T 1 - T 2 = mL + mS w T 2 - T 3 By substituting the given values we get, 104 × 4 . 2 × 20 + 42 × 0 . 4 × 20 = 336 x + x 4 . 2 × 10 8736 + 336 = 378 x x = 9072 378 = 24 g . Hence, the mass added is 24 g .

The melting point of naphthalene is 80 ° C and the room temperature is 30 ° C . A sample of liquid naphthalene at 100 ° C is cooled down to the room temperature. Draw a temperature time graph to represent this cooling. In the graph, mark the region which corresponds to the freezing process.

As naphthalene is having melting point at 80 ° C , in this zone due to the latent heat of fusion the temperature remains steady at 79 ° C (Freezing point of napthalene) as the napthalene solidifies as shown by the portion BC of the curve. This happens even though thermal energy is being lost to the surroundings. There is no change in temperature. This is basically Freezing process zone.

Name the material used for making a Calorimeter. Why is a Calorimeter made up of thin sheets of the this material?

The Calorimeter box is made up of Copper. A calorimeter is a device used to measure the quantity of heat transferred to or from an object. Cu is highly malleable, and hence very thin box of small mass can be made. Copper is a good conductor of heat. Calorimetry is the process of measuring the amount of heat released or absorbed during a chemical reaction. A calorimeter box is made up of Copper because (i) Cu has low specific heat capacity, and thus it reaches the equilibrium temperature quickly by absorbing a small amount of heat. (ii) Cu is highly malleable and hence a very thin box of small mass can be made thus decreasing the heat capacity of the box. This makes sure the calorimeter absorbs or liberates a small amount of heat during the heat exchange.

Calorimetry is the study that related with determining the changes in energy of a system by measuring the heat exchanged with the surroundings and by this holding the law of conservation of energy.

The diagram above shows a circuit with the key k open. Calculate the resistance of the circuit when the key k is closed. Calculate the current drawn from the cell when the key k is closed.

Data given, voltage V = 3 . 3 V , When the key k is closed resistance 2 Ω and 3 Ω are in series. If equivalent resistance is R 1 then R 1 = 2 Ω + 3 Ω = 5 Ω This R 1 and 5 Ω are in parallel so if equivalent resistance is R 2 then: R 2 = R 1 × 5 R 1 + 5 = 5 × 5 5 + 5 = 25 10 = 2 . 5 Ω R 2 and internal resistance of the battery ( 0 . 5 Ω ) are connected and they are in series. If equivalent resistance is R T , so R T = 2 . 5 Ω + 0 . 5 Ω = 3 Ω Hence, the Resistance of the circuit when key K is closed is 3 Ω By ohm's law I = V R = V R T = 3 . 3 V 3 Ω = 1 . 1 A Thus, the current drawn from the cell when key K is closed is 1 . 1 A .

E M B I B E

Self Study in Physics>Chapter 14 - Latest ICSE Examination Question Paper-2019 (Solved)>SCIENCE PAPER - I (PHYSICS)>Q 10

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10th ICSE

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Earn 100

Draw a neat labeled diagram of an A.C. generator.

Important Questions on Latest ICSE Examination Question Paper-2019 (Solved)

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Self Study in Physics>Chapter 14 - Latest ICSE Examination Question Paper-2019 (Solved)>SCIENCE PAPER - I (PHYSICS)>Q 1

The diagram below shows a claw hammer used to remove a nail:

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(i) To which class of lever does it belong?
(ii) Give one more example of the same class of lever mentioned by you in (i) for which the mechanical advantage is greater than one.

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Self Study in Physics>Chapter 14 - Latest ICSE Examination Question Paper-2019 (Solved)>SCIENCE PAPER - I (PHYSICS)>Q 2

A man playing a flute is able to produce notes of different frequencies. If he closes the holes near his mouth, will the pitch of the note produced, increase or decrease? Give a reason.

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Self Study in Physics>Chapter 14 - Latest ICSE Examination Question Paper-2019 (Solved)>SCIENCE PAPER - I (PHYSICS)>Q 3

Two waves of the same pitch have amplitudes in the ratio