Based on statistical mechanics, entropy of a system is defined as:

• A) The degree of randomness
• B) The degree of molecular attraction
• C) The degree of temperature
• D) The degree of order

In everyday life the effect of diffraction is more significant for sound than for light because that:

• A) Light has a much longer wavelength than sound.
• B) Insufficient Information.
• C) Light has a much shorter wavelength than sound.
• D) Light has a much shorter frequency than sound.

The units of the Planck constant h are those of:

• A) Energy
• B) Frequency
• C) Angular momentum
• D) Momentum

For what purpose would a concave mirror be particularly useful, given its ability to produce virtual images that are smaller?

• A) Rear-view mirrors in cars
• B) Magnifying glasses
• C) Shaving mirrors
• D) Astronomy telescopes

Which of the following does not show any interference pattern?

• A) A thick film
• B) Excessively thin film
• C) A wedged-shaped film
• D) Soap bubble

No entropy change is associated with:

• A) Isobaric process
• B) Isothermal process
• C) Remains constant
• D) Adiabatic process

What happens to the speed of light when it passes from a rare medium to a denser medium?

• A) It becomes zero
• B) It remains the same
• C) It increases
• D) It decreases

Coherent sources of light mean ______________.

• A) They must have same frequency
• B) They must have same amplitude
• C) They must have fixed phase relative to each other
• D) They must have same speeds

Aging process of the human body:

• A) Becomes fast at very high speed
• B) Remains constant
• C) Becomes slow by motion at very high speed
• D) None of these

The special theory of relativity is applicable to the object moving with maximum velocity equal to:

• A) More than speed of light
• B) Double the speed of light
• C) Less than speed of light
• D) Speed of light

The Stefan-Boltzmann constant (σ) has a value of:

• A) 6.67×10−11 N⋅m2/kg2
• B) 5.67×10−8 Watt/(m2⋅K4)
• C) 6.63×10−34 Joule⋅sec
• D) 3×108 m/s

Fermat's principle helps to explain the phenomenon of:

• A) Diffraction
• B) Refraction
• C) Reflection
• D) Dispersion

Length contraction is noticeable only in the direction:

• A) Perpendicular to motion
• B) Along the direction of motion
• C) Orthogonal to motion
• D) Independent of motion

If a lens has a focal length of 15 cm and another has 20 cm, which statement about their strengths in diopters is true?

• A) Strength isn't linked to focal length
• B) 20 cm lens has higher strength
• C) Both lenses have equal strength
• D) 15 cm lens has higher strength

During the time that latent heat is involved in a change of state:

• A) The temperature does not change
• B) Molecular activity remains constant
• C) The substance always expands
• D) A chemical reaction takes place

During a slow adiabatic expansion of a gas:

• A) No energy enters or leaves as heat
• B) The pressure remains constant
• C) Energy is added as heat
• D) Work is done on the gas

Which material would require the most heat to raise its temperature by 1°C?

• A) Metal
• B) Steam
• C) Water
• D) Ice

If the average kinetic energy of molecules in an ideal gas is KE at 200 K, then the average kinetic energy at 600 K will be:

• A) KE2
• B) 4KE
• C) KE3
• D) 3KE

According to the first law of thermodynamics, applied to a gas, the increase in the internal energy during any process:

• A) Equals the work done on the gas minus the heat input
• B) Equals the heat input plus the work done on the gas
• C) Is independent of the work done on the gas
• D) Equals the heat input minus the work done on the gas

Constant-volume gas thermometers using di?erent gases all indicate nearly the same temperature when in contact with the same object if:

• A) The volumes are all the same
• B) The particle concentrations are all extremely small
• C) The pressures are all extremely large
• D) The volumes are all extremely large