Tag: thermal expansion

Questions Related to thermal expansion

When hot liquid is poured into a thick glass tumbler,it cracks

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. Glass is good conductor of heat

  2. Glass is poor conductor of heat

  3. Both

  4. None

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Correct Option: B
Explanation:

When hot liquid is poured into a thick glass tumbler,it cracks.the reason is that the glass is a poor conductor of heat.when a hot liquid is poured into a tumbler ,the inner surface of the tumbler becomes hot,while the outer surface remain at room temperature.

Unit of real expansion

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. $^{\circ} C^{-1}$

  2. $/K$

  3. Both

  4. None

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Correct Option: C
Explanation:

The true increase in the volume of liquid per unit original volume per degree rise in temperature is called the coefficient of real coefficient.

If the pendulum of a clock is made of a metal like steel or brass

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. It's length increases in summer

  2. Time period of oscillation increases

  3. Both

  4. None

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Correct Option: C
Explanation:

If the pendulum of a clock is made of a metal like steel or brass,its length increases in summer due to increase in Temperature ,hence time period of oscillation increases and the clock goes slow.

Coefficient of real expansion

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. Apparent increase in volume/original volume $\times$ rise in temperature

  2. True increase in volume/ original volume $\times$ rise in temperature

  3. Both

  4. None

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Correct Option: B
Explanation:

The true increase in the volume of liquid per unit original volume of liquid per degree rise in temperature is called coefficient of volume expansion.

A heating coil is immersed in a 100g sample of $H _2O(l)$ at 1 atm and $100 \circ C$ in a closed vessel. In this heating process, 60% of the liquid is converted to the gaseous form at constant pressure of 1 atm. The densities of liquid and gaseous water under these conditions are $1000 kg / m^3$ and $0.60 kg /m^3$ respectively. Magnitude of the work done for the process is

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. 4997 J

  2. 4970 J

  3. 9994 J

  4. 1060 J

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Correct Option: A

A liquid column of height $80cm$ at $0^oC$ balances the same liquid of height $80.4cm$ at $100^oC$. ${\gamma} _{R}$ is

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. $4 \times {10}^{-5}/^oC$

  2. $3 \times {10}^{-5}/^oC$

  3. $5 \times {10}^{-5}/^oC$

  4. $6 \times {10}^{-5}/^oC$

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Correct Option: C

When the temperature of the body increases from t to t+Δt, its moment of inertia increases from I to I+ΔI .The coefficient of liner expansion of the body is α. The ratio ΔI/I is equal to:

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. $ \Delta t/I$

  2. $ 2 \Delta t/I$

  3. $ \alpha \Delta t$

  4. $2 \alpha \Delta t$

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Correct Option: D

In Searle's apparatus we have two wires. During experiment we study the extension in one wire. The use of second wire is-

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. to support the apparatus because it is heavy and may not break single wire

  2. to compensate the changes in length caused by changes in temperature of atmosphere during experimentation

  3. to keep the apparatus in level so that extension is measured accurately

  4. all the three above

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Correct Option: C

State applications of thermal expansion.

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. Thermometers

  2. galvanometer

  3. ammeter

  4. voltmeter

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Correct Option: A
Explanation:
Application of thermal expansions are:
1. Rivetting
2. Fitting the steel rim on a horse cart wheel
3. Hot air balloons
4. Thermometers

Real expansion of liquid is :

physics heat and temperature anomalous expansion of water thermal expansion in solids, liquids and gases thermal expansion

  1. independent of expansion of the vessel

  2. dependent on expansion of the vessel

  3. independent of nature of the liquid

  4. depends on both nature of the liquid and vessel

Show answer
Correct Option: A
Explanation:

Real expansion is the expansion of the liquid independent of where it is contained and is a property of the liquid. Apparent expansion will depend on  the container.