Geotechnical Engineering Laboratory Quiz

What is the primary objective of the plastic limit test?

• To determine the maximum water content at which soil flows like a liquid.

• To identify the lowest moisture content at which soil behaves plastically.

• To measure the shrinkage limit of cohesive soils.

• To classify soil based on grain size distribution.

In the plastic limit test, the soil thread must crumble at what diameter?

• 1 mm

• 3 mm

• 6 mm

• 10 mm

How is the plasticity index (PI) calculated?

• PI = LL + PL

• PI = LL / PL

• PI = LL - PL

• PI = PL - LL

Which apparatus is NOT used in the plastic limit test?

• Evaporating dish

• Cone penetrometer

• Glass plate

• Palette knife

What does a plasticity index (PI) of 15 indicate about the soil?

• Non-plastic (sand)

• Low-plastic (silt)

• medium plastic (silty clay)

• Highly plastic (clay)

The purpose of a sieve analysis test is to:

• determine the particle size distribution of a granular material.

• measure the chemical composition of a material.

• assess the color of a material sample.

• test the electrical conductivity of a material.

Which sieve size is typically the smallest used in dry sieve analysis?

• 4.75 mm

• 0.425 mm

• 0.063 mm

• 2.00 mm

What is the correct sequence for arranging sieves in a stack?

• largest opening at the bottom

• smallest opening at the top

• largest opening at the top

• Random order

If the total mass of the dry sample is 200 g and 50 g is retained on the 0.6 mm sieve, what is the % passing?

• 25%

• 50%

• 75%

• 100%

Why is a semilog graph used for particle size distribution curves?

• To linearize exponential data.

• To simplify calculations for plasticity index.

• To represent a wide range of particle sizes clearly.

• To measure moisture content accurately.