Temperature — Set 1
Physics · तापमान · Questions 1–10 of 50
Which law states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other?
Correct Answer: A. Zeroth law of thermodynamics
The zeroth law defines thermal equilibrium and the basis of temperature. If A is in equilibrium with B and B with C, then A is also with C. This idea allows thermometers to compare temperatures reliably.
Temperature is most directly related to which microscopic quantity?
Correct Answer: B. Average kinetic energy of particles
Temperature reflects the average kinetic energy of the particles in a substance. Faster random motion generally means higher temperature. This is why gases expand and exert more pressure when heated.
What is the SI base unit of temperature?
Correct Answer: B. Kelvin
The kelvin is the SI base unit for temperature. It is an absolute scale used in science and engineering. One kelvin step is the same size as one degree Celsius step.
Which statement best describes heat in physics?
Correct Answer: B. Heat is energy transferred due to a temperature difference
Heat is energy that flows from a hotter body to a colder body because of temperature difference. It is not a property contained permanently in a body like mass. Its SI unit is the joule.
Which temperature scale is commonly accepted as an absolute thermodynamic scale?
Correct Answer: D. Kelvin scale
The kelvin scale is an absolute temperature scale starting from absolute zero. It avoids negative values for ordinary equilibrium temperatures. Gas laws are typically written using kelvin.
A temperature of 25°C is equal to approximately how many kelvin?
Correct Answer: A. 298 K
Kelvin temperature is found by adding 273.15 to the Celsius value. So 25 + 273.15 equals 298.15 K, which is about 298 K. The kelvin scale is widely used for scientific temperature calculations.
Which property of mercury helps it give a clear reading in a glass thermometer?
Correct Answer: D. It does not wet glass and forms a distinct meniscus
Mercury does not wet glass, so it forms a sharp meniscus that is easy to read. This improves the clarity of the thermometer column. Mercury also expands fairly uniformly over a useful temperature range.
What is 0°C equal to on the Fahrenheit scale?
Correct Answer: A. 32°F
Use the conversion F = (9/5)C + 32 for Celsius to Fahrenheit. Putting C = 0 gives F = 32. This is why water freezes at 32°F under standard pressure.
Which thermometer is generally more suitable for measuring very low temperatures below the freezing point of mercury?
Correct Answer: C. Alcohol thermometer
Alcohol remains liquid at much lower temperatures than mercury. This allows alcohol thermometers to measure colder conditions. Mercury freezes near about minus 39°C, limiting mercury thermometers.
On the Celsius scale, which fixed points were traditionally used for thermometer calibration at standard pressure?
Correct Answer: C. Ice point 0°C and steam point 100°C
The Celsius scale traditionally uses the ice point and steam point of water at standard pressure. These are set at 0°C and 100°C respectively. Fixed points provide reproducible reference temperatures for calibration.