Pakistan MCQs

Stress is force divided by cross-sectional area.
1000/0.005 = 200,000 Pa.

Young's modulus is stress divided by strain.
2×10^8 / 0.001 = 2×10^11 Pa.

Hooke's law magnitude gives k=F/x.
K=20/0.04 = 500 N/m.

Temperature indicates how energetic particle motion is on average.
It determines the direction of spontaneous heat transfer.

Heat is energy in transit between systems.
It flows spontaneously from higher to lower temperature.

Systems in thermal equilibrium have the same temperature.
This idea underlies the zeroth law of thermodynamics.

If two systems are each in thermal equilibrium with a third, they are in equilibrium with each other.
This permits consistent temperature measurement.

Specific heat capacity describes thermal inertia.
Materials with high values require more heat for the same temperature rise.

Latent heat changes molecular arrangement rather than temperature.
Fusion and vaporization involve different latent heats.

Heating usually increases average particle separation.
Solids, liquids, and gases expand by different amounts.

Conduction transfers energy through collisions and free electrons.
It is dominant in many solids.

Convection combines fluid motion with thermal energy transport.
It may be natural or forced.