Explanation

• The number of spark plugs needed in a diesel engine is zero
• Diesel engines use compression ignition instead of a spark.
• Air is compressed until it is hot enough to ignite the fuel.
• Instead of spark plugs, they use glow plugs to warm the engine when cold

Explanation

• A change of 1 Kelvin (K) is equal in magnitude to a change of 1 degree Celsius (°C).
• Therefore, a rise of 10 K equals a rise of 10°C.
• The numerical values of Kelvin and Celsius differ when expressing an actual temperature, but their temperature intervals are equal.

Last verified on 16-10-2026

Explanation

• Strain is the ratio of the change in length to the original length of a material when a force is applied.
• It measures the relative deformation of a material.
• It has no unit, because it is a ratio of two lengths.

Last verified on 16-10-2026

Explanation

• Surface tension decreases as temperature increases.
• Higher temperature increases the kinetic energy of liquid molecules, weakening the effect of intermolecular cohesive forces at the surface.
• Surface tension becomes nearly zero at the critical temperature, where the distinction between liquid and gas disappears.
• Water has a surface tension of approximately 72.8 mN/m at 20°C.

Last verified on 16-10-2026

Explanation

• Nitrogen (N₂) → 78%

Additional information:

• Oxygen (O₂) → 21%
• Argon (Ar) → 0.93%
• Carbon dioxide (CO₂) → 0.04% (approximately)
• Other gases → Trace amounts

Last verified on 28-06-2026