ME Christmas party 2024

At what temperature does helium become a liquid?

• -183°C

• -269°C

• -196°C

• -273°C

Answer explanation

Helium becomes a liquid at -269°C, which is its boiling point at standard atmospheric pressure. This temperature is crucial for understanding helium's unique properties as a cryogenic liquid.

Which material is most commonly used for superconducting applications in cryogenics?

• • Copper

• Lead

• • Niobium

• • Iron

Answer explanation

Niobium is the most commonly used material for superconducting applications in cryogenics due to its high critical temperature and excellent superconducting properties, making it ideal for various applications.

What temperature is considered "absolute zero"?

• -272.15°C

• -271.15°C

• -274.15°C

• -273.15°C

Answer explanation

Absolute zero is defined as the lowest possible temperature, where molecular motion stops. This temperature is -273.15°C, which is equivalent to 0 Kelvin. Therefore, the correct answer is -273.15°C.

Which phenomenon occurs at temperatures near absolute zero?

• Spontaneous combustion

• Bose-Einstein condensation

• Plasma formation

• Crystallization of helium

Answer explanation

Bose-Einstein condensation occurs at temperatures close to absolute zero, where a group of atoms occupies the same quantum state, behaving as a single quantum entity. This phenomenon is distinct from the other options listed.

What happens to electrical resistance in a superconductor below its critical temperature?

• It increases linearly

• It remains constant

• It drops to zero

• It fluctuates randomly

Answer explanation

In a superconductor, when the temperature falls below its critical temperature, electrical resistance drops to zero, allowing for perfect conductivity without energy loss.

Which scientist discovered the concept of superconductivity?

• Marie Curie

• Albert Einstein

• Max Planck

• Heike Kamerlingh Onnes

Answer explanation

Heike Kamerlingh Onnes discovered superconductivity in 1911 when he observed that mercury exhibited zero electrical resistance at very low temperatures, marking a significant breakthrough in physics.

Which year was Bluefors founded?

• 2008

• 2006

• 2009

• 2010

Answer explanation

Bluefors was founded in 2008, making it the correct choice among the options provided. The other years listed do not correspond to the founding year of the company.

What happens to helium at temperatures below 2.17 Kelvin?

• It becomes a solid

• It becomes a superfluid

• It evaporates

• It forms crystals

Answer explanation

At temperatures below 2.17 Kelvin, helium transitions into a superfluid state, exhibiting unique properties like zero viscosity. This phenomenon occurs instead of solidification or evaporation.

What is the key characteristic of a superfluid?

• Zero viscosity

• High viscosity

• High thermal conductivity

• High density

Answer explanation

The key characteristic of a superfluid is its zero viscosity, allowing it to flow without resistance. This unique property enables superfluids to exhibit behaviors like climbing walls and flowing through tiny openings.

What’s the real reason scientists love Bluefors systems?

• They reach ultra-low temperatures for experiments

• They look super cool in the lab photos

• They come with free coffee mugs

• They make your lab the coldest hangout spot

Answer explanation

Scientists love Bluefors systems because they look super cool in lab photos, adding an aesthetic appeal to their research environment. While they do reach ultra-low temperatures, the visual impact is a fun reason to appreciate them.