A soil sample has an Exchangeable sodium percentage (ESP) of 16%, its electrical conductivity is 3.2 Milli-Mohs/cm and a pH of 9.5. How is the soil classified?

Measurement of K_La in a bioreactor can be carried out by sodium sulfite oxidation method, that is, based on the oxidation of sodium sulfite to sodium sulfate in the presence of a catalyst (Cu⁺⁺ or Co⁺⁺). In a typical experiment, a laboratory fermenter was filled with 5 liter of 0.5 M sodium sulfite solution containing 0.003 M Cu⁺⁺ ions and the air was sparged in. After 10 min, the air flow was stopped and a 10 mL sample was taken and titrated. The concentration of sodium sulfite in the sample was found to be 0.20 M. The oxygen uptake rate for this aerated system will work out to be

A

0.08 g L^-1 s^-1

B

0.008 g L^-1 s^-1

C

0.8 g L^-1 s^-1

D

None of the above

Which of the following statements are true with regards to the selection of a sample size? (i) The sample size (n) may be a fixed percentage of lot size (N). (ii) The sample size (n) may be kept constant irrespective of lot size (N). (iii) Sample size (n) can be selected at the personal whim of the inspector.

A

i only

B

i, ii only

C

i, ii, iii

D

i, iii only

For better resistance welding, the metal must have
P. high electrical resistivity and low melting point
Q. high thermal conductivity
R. high electrical resistivity and high melting point
S. low thermal conductivity

A

P, Q

B

P, S

C

R, Q

D

R, S

The exchangeable sodium ratio (ESR) can be calculated as

A

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}$$

B

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{\sqrt {{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)} }}$$

C

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {{\text{K}}^ + }} \right)}}$$

D

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}$$

If the contents of exchangeable ions (cmol kg^-1) determined in soil are Na⁺ = 5, K⁺ = 5, Ca²⁺ = 10, Mg²⁺ = 2, H⁺ = 1, Al⁺³ = 1, Cl^- = 1.6 and HCO^-₃ =0.4, the CEC of soil is

A

26 cmol (P⁺) kg^-1

B

20 cmol (P⁺) kg^-1

C

24 cmol (P⁺) kg^-1

D

None of these

A researcher conduct a hypothesis test and observes values from sample mean and sample standard deviation when n = 25, that do not lead to rejection of null hypothesis. He calculates the p value as 0.0667. What will happen to the p value if he observes the same sample mean and standard deviation for a sample > 25?

A

Stay the same

B

Increase

C

Decrease

D

May increase or decrease

A student was studying primate uterine thickness. She had 3 samples of uterine tissues. The thickness in mm for the samples are as follows: Sample A – 4 mm, Sample B – 10 mm, Sample C – 1 mm Given the knowledge of menstrual cycle in humans, what phases do you think each sample belongs to?

A

Sample A: Menstrual phase, Sample B: Follicular phase, Sample C: Luteal phase

B

Sample A: Proliferative phase, Sample B: Luteal phase, Sample C: Menstrual phase

C

Sample A: Secretory phase, Sample B: Menstrual phase, Sample C: Proliferative phase

D

Sample A: Menstrual phase, Sample B: Secretory phase, Sample C: Follicular phase

In a test of differences between proportions, two samples are taken. In the first sample, a sample size of 100 shows 25 successes. In the second sample, a sample size of 80 shows 25 successes. What would be the value of B in this case?

A

$$\frac{{30}}{{100}} + \frac{{25}}{{80}}$$

B

$$\frac{{30}}{{100}} \times \frac{{25}}{{80}}$$

C

$$\frac{{30 + 25}}{{100}}$$

D

$$\frac{{30}}{{100}} + \frac{{25}}{{180}}$$

A soil, which has pH varies between 7.5 to 8.5 and ESP less than 15 and total soluble salt content is more than 0.11, the soil is called

A

Saline soil

B

Alkaline soil

C

Both A and B

D

None of these

A soil, which has pH ranges from 8.5 to 10 and ESP is greater than 15 and EC less than 4 m mhos/cm, the soil is called

A

Saline soil

B

Alkaline soil

C

Saline alkaline soil

D

None of these

A soil sample has an Exchangeable sodium percentage (ESP) of 16%, its electrical conductivity is 3.2 Milli-Mohs/cm and a pH of 9.5. How is the soil classified?

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