### Soil Mechanics - Basic Concepts

Q.1. Activity of a clay is given by

Activity = N/clay formation(%), here N stands for

(a) liquidity index

(b) plasticity index

(c) flow index

(d) none of these (AMIE Summer99)

Q.2. Lists I and II contain respectively terms and expressions related to soil classifications. Match the two lists and select the correct answer using the codes given below.

List I

A. Activity number

B. Liquidity index

C. Sensitivity

List II

1.

2.

3. (Natural water content - plastic limit)/plasticity index

4. Unconfined compressive strength of undisturbed soil sample divided by unconfined compressive strength of remoulded soil sample

(a) A1,B3,C4

(b) A1,B2,C3

(c) A3,B2,C1

(d) A2,B3,C4 (IES 1993)

Q.3. The plasticity index and the percentage of grain size finer than 2 microns of a clay sample are 25 and 15 respectively. Its activity ratio is

(a) 2.5

(b) 1.67

(c) 1.0

(d) 0.6 (IES 2001)

Q.4. If an unconfined compressive strength of 4 kg/cm2 in the natural state of clay reduces by four times in the remoulded state, then its sensitivity will be

(a) 1

(b) 2

(c) 4

(d) 8 (IES 1999)

Q.5. A soil has a liquid limit of 60%; plastic limit of 35% and shrinkage limit of 20% and it has a natural moisture content of 50%. The liquidity index of soil is

(a) 1.5

(b) 1.25

(c) 0.6

(d) 0.4 (IES 1996)

Q.6. A soil has plasticity index equal to 34%. It has 23% particles having size less than 2 micron.Its activity number would be

(a) 0.67

(b) 1.48

(c) -0.12

(d) none of these

Q.7. The liquid limit and plastic limit of a sample are 65% and 29% respectively. The percentage of the soil fraction with grain size finer than 0.002 mm is 24. The activity ratio of the soil sample is

(a) 0.5

(b) 1.00

(c) 1.50

(d) 2.00 (IES 1995)

Q.8. In a soil sample, dia. of 60% size = 0.0060 mm and dia of 10% size = 0.0005 mm. Its uniformity coefficient will be

(a) 12

(b) .83

(c) 0.08

(d) none of these

Q.9. Data for a given soil sample is: liquid limit = 49.1%; Plastic limit = 26.5 % and natural water content is 45.6%. Consistency index of the soil would be

(a) 0.845

(b) 0.1545

(c) 6.45

(d) none of these

Q.10. A sample of soil has the following properties:

Liquid limit = 45%

Plastic limit = 25%

Shrinkage Limit = 17%

Natural Moisture Cont. = 30%

The consistency index of soil is

(a) 15/20

(b) 13/20

(c) 8/20

(d) 5/20 (IES 1994)

Activity = N/clay formation(%), here N stands for

(a) liquidity index

(b) plasticity index

(c) flow index

(d) none of these (AMIE Summer99)

Q.2. Lists I and II contain respectively terms and expressions related to soil classifications. Match the two lists and select the correct answer using the codes given below.

List I

A. Activity number

B. Liquidity index

C. Sensitivity

List II

1.

2.

3. (Natural water content - plastic limit)/plasticity index

4. Unconfined compressive strength of undisturbed soil sample divided by unconfined compressive strength of remoulded soil sample

(a) A1,B3,C4

(b) A1,B2,C3

(c) A3,B2,C1

(d) A2,B3,C4 (IES 1993)

Q.3. The plasticity index and the percentage of grain size finer than 2 microns of a clay sample are 25 and 15 respectively. Its activity ratio is

(a) 2.5

(b) 1.67

(c) 1.0

(d) 0.6 (IES 2001)

Q.4. If an unconfined compressive strength of 4 kg/cm2 in the natural state of clay reduces by four times in the remoulded state, then its sensitivity will be

(a) 1

(b) 2

(c) 4

(d) 8 (IES 1999)

Q.5. A soil has a liquid limit of 60%; plastic limit of 35% and shrinkage limit of 20% and it has a natural moisture content of 50%. The liquidity index of soil is

(a) 1.5

(b) 1.25

(c) 0.6

(d) 0.4 (IES 1996)

Q.6. A soil has plasticity index equal to 34%. It has 23% particles having size less than 2 micron.Its activity number would be

(a) 0.67

(b) 1.48

(c) -0.12

(d) none of these

Q.7. The liquid limit and plastic limit of a sample are 65% and 29% respectively. The percentage of the soil fraction with grain size finer than 0.002 mm is 24. The activity ratio of the soil sample is

(a) 0.5

(b) 1.00

(c) 1.50

(d) 2.00 (IES 1995)

Q.8. In a soil sample, dia. of 60% size = 0.0060 mm and dia of 10% size = 0.0005 mm. Its uniformity coefficient will be

(a) 12

(b) .83

(c) 0.08

(d) none of these

Q.9. Data for a given soil sample is: liquid limit = 49.1%; Plastic limit = 26.5 % and natural water content is 45.6%. Consistency index of the soil would be

(a) 0.845

(b) 0.1545

(c) 6.45

(d) none of these

Q.10. A sample of soil has the following properties:

Liquid limit = 45%

Plastic limit = 25%

Shrinkage Limit = 17%

Natural Moisture Cont. = 30%

The consistency index of soil is

(a) 15/20

(b) 13/20

(c) 8/20

(d) 5/20 (IES 1994)

**Answer:**

1. b

2. d

3. b

4. c

5. c

6. d

7. c

8. a

9. b

10. b

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These questions are taken from the book "Objective Questions (Civil Engineering)". The Kindle edition of this book is available at just ₹ 99/- only!