Tag: measurement and effects of heat

Questions Related to measurement and effects of heat

The quantity of heat required to raise the temperature of 2000 g of water from 10$^o$C to 50$^o$C is

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. 80 cal

  2. 80,000 cal

  3. 8000 cal

  4. none of these

Show answer
Correct Option: B
Explanation:

Heat required $=mS\triangle T \ =2000\times 1\times (50-10) \ =80000cal$

The quantity/ quantities that does/do not have mass in its/their dimensions is/are

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. Specific heat

  2. Latent heat

  3. Electrical potential difference

  4. Electrical resistance

Show answer
Correct Option: C,D
Explanation:

Specific heat- $J/kg^oC$
Latent Heat- J/kg
Electrical potential difference- J/coulumb
Electrical resistance- ohm
 Hence, option C and D are correct

When 60 calories of heat are supplied to 15 g of water, the rise in temperature is

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. $75^{\circ}C$

  2. $90^{\circ}C$

  3. $4^{\circ}C $

  4. $0.25^{\circ}C$

Show answer
Correct Option: C
Explanation:

$Heat = m S \Delta T$
$\Rightarrow 60=15\times 1\times\triangle T \ \Rightarrow \triangle T=4^oC$

Calorimeters are generally made of

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. copper

  2. brass

  3. aluminium

  4. zinc

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Correct Option: A
Explanation:
Calorimeters is made of copper because:
1) Copper has low specific heat capacity and thus it reaches equilibrium temperature quickly by absorbing small amount of heat.

2) Cu is highly malleable and hence very thin box of small mass can be made, thus decreasing heat capacity of box.

3) Cu is good conductor of heat.

On which law does the study of calorimetry based?

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. Joule's law

  2. Law of conservation of energy

  3. Law of Kinetic energy

  4. None

Show answer
Correct Option: B
Explanation:

Principle of calorimetry states that heat lost by a hotter body = heat gained by a colder body, therefore in calorimetry, total heat energy of the system remains constant, which is the law of conservation of energy . 

When 60 calories of heat are supplied to 15 g of water, the rise in temperature is

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. $75^\circ C$

  2. $900^\circ C$

  3. $4^\circ C$

  4. $0.25^\circ C$

Show answer
Correct Option: C
Explanation:

We know that, $heat=mass\times specific \;heat\times change\;in\;temperature \ \Rightarrow 60=15\times 1\times \triangle T \ \Rightarrow \triangle T=4^oC$

A thermos bottle containing coffee is vigorously shaken. If the coffee is considered as a system, then the temperature of the coffee will 

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. increase slightly

  2. fall

  3. remain the same

  4. never be determined

Show answer
Correct Option: A
Explanation:
A thermoflask is closed system, so no heat energy added to system i.e. $\triangle \theta=0$
Work is done on the system by shaking it against viscous force. Hence $\triangle w=-ve$
Internal energy, $\triangle U=\triangle \theta - \triangle w=0-(-\triangle w) \\ \Rightarrow \triangle U=+\triangle w$
$\because \triangle U\; is\; +ve$ So there is increase in temperature due to rise in internal enrgy.

The branch of physics that deals with the measurement of heat energy is known as

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. Fermentation

  2. Latent heat

  3. Calorimetry

  4. Hidden heat

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Correct Option: C
Explanation:

Calorimetry is the branch of physics which deals with the measurement of heat energy. Calorimetry is one of the methods for the determination of specific heats or latent heats of the substances.

A thermometer is used to measure 

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. heat

  2. thermal capacity

  3. water equivalent

  4. temperature

Show answer
Correct Option: D
Explanation:
A thermometer is used to measure temperature.
Thermo(heat)             meter(measuring device)
It measures temperature in either celcius or farenheit scale.

Heat is added to a block of ice of mass $m$ until the entire block melts into liquid water. Identify by which of the following method this can be explained ?

physics measurement and effects of heat heat exchange calorimeter measuring thermal quantities by the method of mixtures

  1. First law of thermodynamics (conservation of energy)

  2. Second law of thermodynamics (law of entropy)

  3. Ideal gas law

  4. Heat of fusion and heat of vaporization equation

  5. Heat engine efficiency

Show answer
Correct Option: D
Explanation:

When heat is added to ice at $0^{\circ}C$, the temperature of the ice does not change. However the heat goes into the latent heat of fusion of ice, This is a kind of potential energy that water owns in form of latent heat.

Hence correct answer is option D.