A casting defect which occurs due to improper venting of sand is known as

Mr.Rohan while helping the students of Class IV in adding and subtracting fractions observed that several students are not able to complete the addition of two improper fractions. He gave a small test with questions from the addition of proper fractions (one item of addition of two similar fractions, three items from the addition of proper and improper fractions, and four items from the addition of improper fractions). He analyzed the responses of each student and found that nearly 45% of students were not clear in adding proper with improper fractions which were affecting their performance in adding two improper fractions. He, therefore, focused on developing the understanding of improper fractions and their addition with proper fractions after which he proceeded to teach the addition of two improper fractions. Which kind of assessment is depicted by this situation?

A

Assessment OF Learning

B

Assessment for Learning

C

Assessment AS Learning

D

Assessment by learning

A casting defect which occurs due to improper venting of sand is known as?

A

Cold shuts

B

Blow holes

C

Shift

D

Hot tear

Improper venting during moulding process causes a diesel effect which further results in stress crack defects in the casting.

A

True

B

False

The following are certain operating problems of a rapid sand filter: 1. Sand depth should never be depleted by more than 10 cm. 2. Air binding results due to development of negative head and formation of air bubbles in the filter sand. 3. Water softening with lime-soda leads to incrustation of sand. 4. Bumping of filter bed is caused due to negative head. Which of the above statements are correct?

A

1, 2 and 4 only

B

1, 2 and 3 only

C

3 and 4 only

D

1, 2, 3 and 4

Which of the following statements are correct pertaining to the value of uniformity coefficient Cu for filter sand? (1) For slow sand filters, Cu = 1.8 to 2.5 (2) For rapid sand filters, Cu = 1.3 to 1.7 (3) For slow sand filters, Cu = 1.3 to 1.7 (4) For rapid sand filters, Cu = 1.8 to 2.5

A

2 and 3

B

1 and 4

C

3 and 4

D

1 and 2

Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters.Reason R: The sand used in slow sand filters is finer than that in rapid sand filtersSelect your answer based on the coding system given below:

A

Both A and R is true and R is the correct explanation of A

B

Both A and R is true but R is not the correct explanation of A

C

A is true but R is false

D

A is false but R is true

Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters.
Reason R: The sand used in slow sand filters is finer than that in rapid sand filters
Select your answer based on the coding system given below:

A

Both A and R is true and R is the correct explanation of A

B

Both A and R is true but R is not the correct explanation of A

C

A is true but R is false

D

A is false but R is true

Statement I): Incrustation of sand occurs in rapid sand filter when water softened by lime-soda is fed in for filtration. Statement II): The sand gets coated with precipitates of Ca(OH)2 and Mg(OH)2 generated during softening of water by lime-soda process which leads to incrustation of sand.

A

Both Statement I) and Statement II) are individually true and Statement II) is the correct explanation of Statement I)

B

Both Statement I) and Statement II) are individually true but Statement II) is not the correct explanation of Statement I)

C

Statement I) is true but Statement II) is false

D

Statement I) is false but Statement II) is true

Which of the following statements are true about quicksand? i. It is only a condition but not a type of sand. ii. It is a condition and a type of sand too. iii. Quicksand condition reaches when critical hydraulic gradient is approximately equal to unity. iv. Quicksand condition occurs more commonly in coarse grained sand or gravels than fine sand.

A

Both statements ii and iii are true

B

Statements ii, iii and iv are true

C

Both statements i and iii are true

D

Statements i, iii and iv are true

Improper venting arrangement causes mechanical trapping of gases in metal castings.

A

True

B

False

A casting defect which occurs due to improper venting of sand is known as

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