Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

The amount or degree of yarn twist is measured in number of TPI. Give full form of TPI a. Texture per inch b. Turns per inch c. Thickness per inch d. Texture per inch

Answer»

b. Turns per inch

The amount or degree of yarn twist is measured in number of TPI. full form of TPI is Turns per inch.

2.

Which type of steering gear box is used in Swaraj Mazda a) Worm and Worm wheel b) Worm and Sector c) Rack and Pinion d) Worm and Nut

Answer»

Correct answer is d) Worm and Nut

3.

A continuous process is set up for treatment of wastewater. Each day, 10^3 kg cellulose and 10^5 kg bacteria enter in the feed stream, while 10^2 kg cellulose and 1.5 x 10^2 kg bacteria leave in the effluent. The rate of cellulose digestion by the bacteria is 8 x 10^2 kg d^-1. The rate of bacterial growth is 4x 10^2 kg d^-l; the rate of cell death by lysis is 6 x 10^2 kg d^-1. Write balances for cellulose and bacteria in the system.(a) 1× 10^3 kg, 9 × 10^3 kg(b) 1× 10^2 kg, 9.965 × 10^4 kg(c) 1× 10^3 kg, 9.964 × 10^4 kg(d) 1× 10^2 kg, 9 × 10^3 kg

Answer» Right answer is (b) 1× 10^2 kg, 9.965 × 10^4 kg

Easiest explanation: Cellulose is not generated by the process, only consumed. Using a basis of 1 day, the cellulose balance in kg is :

(10^3 – 10^2 + 0 – 8 x 10^2) = accumulation

Therefore, 1× 10^2 kg cellulose accumulates in the system each day.

Performing the same balance for bacteria:

(10^5 – 1.5 x 10^2 + 4 x 10^2 – 6 x 10^2) = accumulation

Therefore, 9.965 × 10^4 kg bacterial cells accumulate in the system each day.
4.

If a drug undergoes net tubular secretion, its renal clearance will be: A. More than the glomerular filtration rate B. Equal to the glomerular filtration rate C. Less than the glomerular filtration rate D. Equal to the rate of urine formation 

Answer»

A. More than the glomerular filtration rate

5.

What does the term Positive pressure means?(a) The contaminants of the room should not flow out into the surrounding(b) There should be the balance between the room and surrounding of air and contaminants(c) The pressure makes room isolated from the surrounding and contaminants(d) The air pressure is lower than the surrounding

Answer» Correct answer is (c) The pressure makes room isolated from the surrounding and contaminants

To explain: Positive pressure refers to pressure that exceeds the surrounding pressure of any room, chamber or confined space. Positive pressure is maintained in a closed zone to ensure no outside contaminated gaseous or liquid substance can get into that protected zone.
6.

On which type of plot the best fit line is represented?(a) Dot plot(b) Line weaver- Burk plot(c) Scatter plot(d) Bland- Altman plot

Answer» Correct answer is (c) Scatter plot

The explanation: A line of best fit is a straight line drawn through the center of a group of data points plotted on a scatter plot. Scatter plots depict the results of gathering data on two variables. The line of best fit shows whether these two variables appear to be correlated and can be used to help identify trends occurring within the dataset. Analysts may use the line of best fit when determining a relationship between two variables where one variable is independent and one variable is being examined for dependency.
7.

What do you mean by the splitting point?(a) The two streams split with different composition(b) The two streams split with equal composition(c) Assuming it’s not a reactor and there’s only 2 streams(d) Assuming it’s not a reactor and there’s only 1 stream

Answer» Right answer is (b) The two streams split with equal composition

Easy explanation: Splitting Point: 6 variables – 2 mass balances – 1 knowing compositions are the same – 1 splitting ratio = 2 DOF (Degree of freedom). The splitting point is special because when a stream is split, it generally is split into two streams with equal composition.
8.

What is the applied centrifugal field at a point equivalent to 5 cm from the centre of rotation and an angular velocity of 3000 rad s^-1?(a) 4.5 × 10^-7 cm s^-2(b) 5.4 × 10^-7 cm s^-2(c) 3.4 × 10^-7 cm s^-2(d) 6.5 × 10^-7 cm s^-2

Answer» Correct choice is (a) 4.5 × 10^-7 cm s^-2

For explanation I would say: The centrifugal field G, at a point 5 cm from the centre of rotation may be calculated using the equation G = ω^2 r,

G = (3000)^2 × 5 cm s^-2 = 4.5 × 10^-7 cm s^-2.
9.

Why is Procaine used in the process of production of Penicillin?(a) Because Procaine is antibiotic in nature(b) Because Procaine is antifungal in nature(c) Because Procaine is analgesic in nature(d) Because Procaine is anti-allergic in nature

Answer» The correct option is (c) Because Procaine is analgesic in nature

To explain: Procaine is an analgesic in nature as it is primarily used to reduce the pain of intramuscular injection of Penicillin and which is also the derivative of cocaine probably provides the longevity to Penicillin.
10.

The manipulated variable levels Continuous (i.e. time in years) or Clumped into groups( i.e. 0-5 years, 6-10 years) is represented as _________(a) Continuous- Scatter plot/line, Clumped- Histogram(b) Continuous- Histogram, Clumped- Scatter plot/line(c) Continuous- Pie chart, Clumped- Scatter plot/line(d) Continuous- Pie chart, Clumped- Histogram

Answer» Correct answer is (a) Continuous- Scatter plot/line, Clumped- Histogram

Explanation: HISTOGRAM :

Histograms are similar to bar graphs except the data represented in histogram is usually in groups of continuous numerical (quantitative) data. In this case, the bars do touch. Histograms are often used to show frequency data.

Example- Average mean temperature between the years 1900 and 2000

SCATTER- PLOT:

The points are plotted on the grid, but they are not joined point to point. A best fit line may be added to a scatter plot to show a trend. Line graphs are only used when both variables are quantitative. These graphs are useful for showing if a correlation exists between two variables, especially when it is not possible to alter either of the variables (i.e. in descriptive studies).

Example – Reaction rate at various enzyme concentrations.
11.

What is Slurry which is used in the Penicillin production process?(a) Semi – Liquid mixture(b) Solid – Liquid mixture(c) Gas – Liquid mixture(d) Liquid

Answer» The correct answer is (a) Semi – Liquid mixture

The best explanation: The Semi – Liquid mixture also known as “Undigested Slurry “which goes under the fermentation / anaerobic process and later on comes out as byproduct of fermentation process as “Digested Slurry”.
12.

Madhur, Mukesh and Mitali ride from home to their common office with speeds in the ratio 7:8:9. If in total they take 95 minutes and 30 seconds (sum of the individual time taken) to cover the individual distance(which is same for all), then find the time taken by Mitali to cover the distance.1. 24 min2. 28 min3. 32 min4. 36 min

Answer» Correct Answer - Option 2 : 28 min

As we know, time taken is inversely proportional to the speed if the distance covered is constant.

Thus, the ratio of the time taken by Madhur, Mukesh and Mitali = (1/7):(1/8):(1/9) = 72:63:56

Let time taken by Madhur, Mukesh and Mitali be 72x, 63x and 56x min respectively.

So, 72x + 63x + 56x = 95.5 x = 95.5/191 = 0.5

Hence, the time taken by Mitali = 56x = 56 × 0.5 = 28 min

13.

Pressure is determined as force per unit area of the surface. The `SI` unit of pressure, pascal is as shown below: `1 Pa=N m^(-2)` If the mass of air at sea level is `1034 g cm^(-2)`, calculate the pressure in pascal.

Answer» Pressure is the force (i.e., weight) acting per unit area But weight=mg
`:.` Pressure = Weight per unit area
`=(1034 gxx9.8 m s^(-2))/(cm^(2))`
`=(1034 gxx9.8 m s^(-2))/(cm^(2))xx(1 kg)/(1000 g)xx(100 cmxx100 cm)/(1 mxx1 m)xx(1 N)/(kg m s^(-2))xx(1 Pa)/(1 N m^(-2))`
`=1.01332xx10^(5) Pa`
14.

What are the two forms of oxygen found in atmosphere? What is their importance?

Answer»

In atmosphere, oxygen is found as
Diatomic molecular form with chemical formula O2 known as oxygen.
Triatomic molecular form with chemical formula O3 known as ozone.
The presence of oxygen in the air (atmosphere) is very essential for the following:
1. The life processes such as respiration, in all living organisms.
2. Combustion of fuels. Otherwise, fire would not have been possible
The presence of ozone in the air (atmosphere) is very essential for the following:
1. Ozone is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (UV) rays from the Sun.

15.

Calculate the degree of unsaturation of the given compound. A. 4B. 5C. 7D. 8

Answer» Correct Answer - C
Molecular formula is `C_(8)H_(4)` thus DBE = 7.
16.

Which of the given subshell follow given relationship `n+l=9`A. 6d,5f,7p,8sB. 7p,8p,9s,6fC. 6f,7d,9s,8pD. 6p,7d,8s,9p

Answer» Correct Answer - C
`{:(n+l=9),(9+0=9s),(8+1=8p),(7+2=7d),(6+3=6f),(5+4=5g):}`
17.

To measure the covalent radius of carbon which of the following molecule is used :A. `C_(2)H_(4)`B. `C_(2)H_(8)`C. `C_(2)H_(2)`D. Both (B) & (C )

Answer» Correct Answer - B
Single bond covalent radius is used to measure covalent radius.
SBCR is calculated in single bonded atoms.
18.

The ratio of gold and silver in an alloy is 7 : 3 respectively. If the weight of the gold in the alloy is 61.6 gm. Find the weight of silver in the alloy.1. 13.2 gm2. 20.0 gm3. 26.4 gm4. 22.4 gm

Answer» Correct Answer - Option 3 : 26.4 gm

Given:

The ratio of gold and silver in an alloy = 7 ∶ 3 

The weight of the gold in the alloy = 61.6 gm

Calculations:

The weight of silver in the alloy = (61.6/7) × 3 = 8.8 × 3 = 26.4 gm

∴ The weight of silver in the alloy is 26.4 gm.

19.

There are two common oxides of sulphur, one of which contains `50% O_(2)` by weight, the other almost exactly `60%`. The weight of sulphur which combine with `1 g` of `O_(2)` (fixed) are in the ratio ofA. `1:1`B. `2:1`C. `2:3`D. `3:2`

Answer» Correct Answer - D
In` "I" ^(st)` oxide
50 gm O combine with 50 gm S
1 gm O combine with 1 gm S
In `"II"^(nd)`oxide
60 gm O combine with 40 gm S
1 gm O combine with 40 gm S
Ratio in which 1 gm O combine with different masses of sulphur 3 :2
20.

Which among the following is a feature of adiabatic expansion ?A. `Delta V lt 0`B. `Delta U lt 0`C. `Delta U gt 0`D. `Delta T = 0`

Answer» Correct Answer - d
For adiabatic expansion there is o change in heat which means no change in tempertature also
dq=0 T= constant
`therefore` dT=0
21.

In the reaction `SO_(2)+H_(2)Sto3S2H_(2)O` the substance oxidised is :-A. SB. `SO_(2)`C. `H_(2)S`D. `H_(2)O`

Answer» Correct Answer - C
`overset(+4)SO_(2)+H_(2)overset(-2)Sto3overset(0)S+2H_(2)O`
22.

`A+BtoC+D` `DeltaH=-10,000 J mol^(-1)` `DeltaS-33.3 J mol^(-1)K^(-1)` At what temperature the reaction will occur spontaneous from left to right ?A. `=300.3K`B. `gt300.3K`C. `lt300.3K`D. None of these

Answer» Correct Answer - C
`DeltaG=0=0Delta-TDeltaS`
`T=(-10000)/(-3.3)=300.3K` Since `DeltaH&DeltaH` both are negative therefore reaction will be sportaneous at `Tlt300.3K`
23.

Construct a cell from `Ni^(2+) | Ni` and `Cu^(2+) |Cu` half cells. Write the cell reaction and calculate the standard potential of the cell `E_(Ni)^(@) = 0.236 V` and `E_(Cu)^(@) = 0.0337 V`

Answer» (i) Voltaic Cell : `Ni_((s)) | Ni_((aq))^(2+) (1 M) "||" Cu_((aq))^(2+) (1 M) | Cu_((s)) `
(ii) Cell reaction `: Ni_((s)) + Cu_((aq))^(2 + ) to Ni_((aq))^(2+) + Cu_((s))`
(iii) `E_(" cell ")^(@) = 0.573 V`
24.

The cell reaction for a galvant cell is `H_(2(g)) + C1_(2(g)) to 2HC1_((aq))` Construct the cell and also calculate standard emf of cell `E_(C1)^(@) = 1.36 V`

Answer» Cell for the given reaction
`Pt, H_(2(g)) (1 atm) | underset(1 M) (HC1_((aq))) | C1_(2(g)) ( 1 atm) ,Pt , E_(" cell ")^(@) = 1.36 V`
25.

If A(2, –1), B(3, 4), C(–2, 3) are the vertices of a triangle find the fourth vertex.

Answer»

Difference between x coordinates of A and B = 3 – 2 = 1, 

Coordinate of y = 4 + 1 = 5 

x coordinates of D = –2 – 1 = -3

y coordinates of D = 3 – 5 = –2 

Coordinates of D = (–3, –2)

26.

What is the equation of the circle? Centre (2, 1), radius √5.

Answer»

Equation of the circle

(x – 2)2 + (x – 1)2 = 5

x2 – 4x + 4 + y2  – 2y + 1 = 5

x2 + y– 4x – 2y = 0

27.

Prove that if (x, y) be a point on the circle with the line joining (0, 1) and (2, 3) as diameter, then x2 + y2 – 2x – 4y + 3 = 0. Find the coordinates of the points where this circle cuts they axis.

Answer»

As (0, 1), (2, 3) are the points joining the diameter of the circle, the center will be

\(=(\frac{0+2}{2},\frac{1+3}{2})=(1,2)\)

Radius = \(\sqrt{(1-0)^2+(2-1)^2}\)

\(\Rightarrow\) r = \(\sqrt{1^2+1^2}=\sqrt{2}\)

(x, y) lies on the cirlce

(x - 1)2 + (y - 2)2\(\sqrt{2}^2\)

x2 - 2x + 1 + y2 - 4y + 4 = 2

x2 + y2 - 2x - 4y + 5 - 2 = 0

x2 + y2 - 2x - 4y + 3 = 0

Let (x, 0) be the coordinate which intersect the x axis then, x2 – 2x + 3 = 0

\(x=\frac{2\pm\sqrt{4-12}}{2}=\frac{2\pm\sqrt{-8}}{2}\)

This circle can not be intersect the x axis. 

Let (0, y) be the coordinate which intersect the y axis then, y – 4y + 3 = 0, (y – 3)(y – 1) = 0 

Coordinates are (0, 1) and (0, 3)

28.

Prove that for any point on the line intersecting the axes in the picture, the sum of the x and y coordinates is 3.

Answer»

If (x, y) lies' on the line joining the points (0,3) and (3,0) then,

\(\frac{y-3}{x-0}=\frac{0-3}{3-0}\)

\(\Rightarrow \frac{y-3}{x}=\frac{-3}{3}=-1\)

y - 3 = x

\(\Rightarrow\) x + y = 3

∴ the sum of the and y coordinates of the point is 3.

29.

One end of the diameter of a circle is (1, 4). The center of the circle is (3, –4). Find the coordinates of other end

Answer»

One end of the diameter = (x , y ) = (1, 4) 

Center of the circle = (x, y) =(3, -4) If other end of the diameter = (x2, y2)

\(3=\frac{1+x_2}{2},\)

∴ x2 = 6 - 1

= 5 - 4 = \(\frac{4+y_2}{2},\)

∴ y2 = -8 - 4 = -12,

Other end of the diameter (5 – 12)

30.

A circle is drawn with origin as the center and radius 10 units. Show that the point (–8, –6) is a point on the circle. Find out whether the point (9, –1) lies within the circle or outside the circle. Why?

Answer»

The distance between the centre and the point (-8,-6) is = \(\sqrt{(-8)^2+(-6)^2}\)

\(\sqrt{100}\) = 10

It is equal to the radius. So the point (-8, -6) is a point on the circle.

The distance between the centre, and the point (9,-1) is = \(\sqrt{9^2+(-1)^2}\)

\(\sqrt{81+1}\) = \(\sqrt{82}\)

√82 is smaller than 10.

So the point (9, –1) is a point inside the circle.

Distance between (x1, y1) and (x3, y2) is

\(\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\)

Distance of (x, y) from (0, 0) is \(\sqrt{x^2+y^2}\)

31.

What is the distance between the origin and the point (–2, -3)? What is the relation between this distance and the distance between the origin and the point (2, 3)?

Answer»

The distance to the points (–2,–3) is \(\sqrt{(-2)^2+(-3)^2}=\sqrt{13}\)

The distance to the points (2, 3) is \(\sqrt{2^2+3^2}=\sqrt{13}\)

Both the distances are equal.

32.

Find the equation of the circle with center at the origin and radius 5. Write the coordinates of eight points on this circle.

Answer»

Equation of the circle

= (x – 0)2 + (y – 0)2 = 52

= x2 + y2 = 25

x2 = 25 – y2

x = \(\sqrt{25-y^2}\)

y = 0 x = 5 (5, 0), (–5, 0)

y = 5 x = 0 (0, 5), (0, –5)

y = 3 x = 4 (4, 3), (4, 3)

y = 4 x = 3 (3, 4), (3, –4)

Coordinates of points on the circle (5, 0), (–5, 0), (0, 5), (0, -5), (4, 3), (4, 3), (3, 4), (3, 4).

33.

A line passing through a point at a distance 4 from the right of origin on x-axis. If (3, –5) is a point on this line, find the equation of the line.

Answer»

Points are (4, 0) (3, –5)

Slope = \(\frac{-5}{-1}=5\)

34.

The points on a line are (–1, 1), (3, 1), (5, 1)What is the angle made by this line with x-axis? What is the slope of this line

Answer»

This line is parallel to the x-axis so the slope is 0.

35.

Find the slope of the line passing through (1, –3) (3, –5).

Answer»

Slope = \(\frac{-5+3}{3-1}=\frac{-2}{2}=1\)

36.

Find the slope of the line given below.

Answer»

Slope of the line = tan 60° = √3

37.

The numbers in the sequence 2, 5, 8,11 and the numbers in the sequence 7, 11, 15, 19 …. are joined pairwise as given below(2, 7), (5, 11), (8, 15) Prove that these are on a line.

Answer»

Distance between (2, 7) and (5, 11) = \(\sqrt{9+16}=5\)

Distance between (5, 11) and (8, 15) = \(\sqrt{9+16}=5\)

Hence the distances are same, so the points are lie on the same line.

38.

If a line cut x-axis at (5, 0) and y-axis at (0, – 3) Find the slope of the line given below.

Answer»

Slope of the line = \(\frac{-3-0}{0-5}=\frac{-3}{-5}=\frac{3}{5}\)

39.

Find the slope of the line passing through (– 2, 3) (5, 7) Write the slope of the fine parallel to it.

Answer»

Slope of the line which passing through the points (–2, 3) and (5, 7) = \(\frac{7-3}{5+2}=\frac{4}{7}\)

The line which joins the points (–2, 2) and (5, 6) is parallel to the first line.

Slope of the line which passes through the points (–2, 2) and (5, 6) = \(\frac{6-2}{5+2}=\frac{4}{7}\)

Slope of the line which passes through the points (–7, 4) and (0, 8) = \(\frac{8-4}{0+7}=\frac{4}{7}\)

The lines are parallel because their slopes are same.

40.

If \([1\,\,\,{-1}\,\,\,\,x]\left[\begin{matrix}0&1&-1\\2&1&3\\1&1&1\end{matrix}\right]\, \left[\begin{matrix}0\\1\\1\end{matrix}\right] =0\), find x.

Answer»

 \([1\,\,\,{-1}\,\,\,\,x]\left[\begin{matrix}0&1&-1\\2&1&3\\1&1&1\end{matrix}\right]\, \left[\begin{matrix}0\\1\\1\end{matrix}\right] =0\) 

⇒ \([1\,\,\,{-1}\,\,\,\,x]\left[\begin{matrix}0\\4\\2\end{matrix}\right] =0\)

⇒ - 4 + 2x = 0

⇒ x = \(\frac42 = 2\)

41.

If A = [2,4,3,2] and B = [-2,5,3,4], then find 3A - B. A = \(\begin{bmatrix}2&4\\3&2\end{bmatrix}\), B = \(\begin{bmatrix}-2&5\\3&4\end{bmatrix}\)

Answer»

A = \(\begin{bmatrix}2&4\\3&2\end{bmatrix}\), B = \(\begin{bmatrix}-2&5\\3&4\end{bmatrix}\)

\(\therefore\) 3A - B = 3\(\begin{bmatrix}2&4\\3&2\end{bmatrix}\) - \(\begin{bmatrix}-2&5\\3&4\end{bmatrix}\)

 = \(\begin{bmatrix}6&12\\9&6\end{bmatrix}\) - \(\begin{bmatrix}-2&5\\3&4\end{bmatrix}\)

 = \(\begin{bmatrix}6-(-2)&12-5\\9-3&6-4\end{bmatrix}\) = \(\begin{bmatrix}8&7\\6&2\end{bmatrix}\)

42.

Find the inverse using elementary row transformation: [1 3 -2] [-3 0 1] [2 1 0]\(\begin{bmatrix}1&3&-2\\-3&0&1\\2&1&0\end{bmatrix}\)

Answer»

Let A = \(\begin{bmatrix}1&3&-2\\-3&0&1\\2&1&0\end{bmatrix}\)

We have A = I A

⇒ \(\begin{bmatrix}1&3&-2\\-3&0&1\\2&1&0\end{bmatrix}\) = \(\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}A\) 

Applying R2 → R2 + 3R1

R3 → R3 - 2R1

\(\begin{bmatrix}1&3&-2\\0&9&-5\\0&-5&4\end{bmatrix}\)\(\begin{bmatrix}1&0&0\\3&1&0\\-2&0&1\end{bmatrix}A\) 

Applying R3 → 9R3 + 5R2

\(\begin{bmatrix}1&3&-2\\0&9&-5\\0&0&11\end{bmatrix}\) = \(\begin{bmatrix}1&0&0\\3&1&0\\-3&5&9\end{bmatrix}A\)

Applying R3 → R3/11

\(\begin{bmatrix}1&3&-2\\0&9&-5\\0&0&1\end{bmatrix}\) = \(\begin{bmatrix}1&0&0\\3&1&0\\-3/11&5/11&9/11\end{bmatrix}A\) 

Applying R1 → R1 + 2R3

R2  → R2 + 5 R3

\(\begin{bmatrix}1&3&0\\0&9&0\\0&0&1\end{bmatrix}\) = \(\begin{bmatrix}5/11&10/11&18/11\\18/11&36/11&45/11\\-3/11&5/11&9/11\end{bmatrix}A\) 

Applying R2 → R2/9

\(\begin{bmatrix}1&3&0\\0&1&0\\0&0&1\end{bmatrix}\) = \(\begin{bmatrix}5/11&10/11&18/11\\2/11&4/11&5/11\\-3/11&5/11&9/11\end{bmatrix}A\)

Applying R1 → R1 - 3R2

\(\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}\) = \(\begin{bmatrix}-1/11&-2/11&3/11\\2/11&4/11&5/11\\-3/11&5/11&9/11\end{bmatrix}A\)

We obtain I = \(\begin{bmatrix}-1/11&-2/11&3/11\\2/11&4/11&5/11\\-3/11&5/11&9/11\end{bmatrix}A\)

\(\therefore\) A-1 = \(\begin{bmatrix}-1/11&-2/11&3/11\\2/11&4/11&5/11\\-3/11&5/11&9/11\end{bmatrix}\)(\(\because\) A-1 A = I)

43.

Scan exceptions

Answer»

Scanning exceptions are lists of trusted or untrusted sites (hostnames and URLs) that are never analyzed or always analyzed. The type of analysis to never or always perform is specified per hostname or URL, or group of hostnames and URLs.

44.

It has been found that the `pH` of a `0.01 M` solution of an orginic acid is `4.15`. Calculate the concentration of the anion, the ionization constant of the acid and its `pK_(a)`.

Answer» `HA hArr H^(o+)+A^(Θ)`
`pH=-log [H^(o+)]` or `log [H^(o+)]=- pH=-4.15=bar(5).85`
`:. [H^(o+)]=7.09xx10^(-5)M=7.08xx10^(-5)M`
`[A^(Θ)]=[H^(o+)]=7.08xx10^(-5)M`
`K_(a)=([H^(o+)][A^(Θ)])/([HA])=((7.08xx10^(-5))(7.08xx10^(-5)))/10^(-2)`
`=5.08xx10^(-7)`
`pK_(a)=-log K_(a) =-log(5.0xx10^(-7))=7-0.699=6.301`
Alternatively
`pH_(W_(A))=1/2(pK_(a)-log C)`
`4.15xx2=pK_(a)-log 10^(-2)`
`8.30-2=pK_(a)`
`pK_(a)=6.30`
45.

Which of the following has pyramidal shape (a) CH​​​​​3​​​​+(b) CH​​​​​3(​​​​​c) CH3-CH2+(d) CH3​​​​--

Answer»

The correct option is  (d) CH3- will go for pyramidal geometry as four electron pairs are distributed in a tetrahedral shape. If there is one lone pair of electrons and three bond pairs the resulting molecular geometry is trigonal pyramidal.

46.

Which of the following statement is incorrect?A. Pure aluminium oxide is obtained by heating aluminium hydroxideB. Cryolite lowers down the melting temperature of bauxite in the electrolytic cell for extraction of aluminiumC. Carbonate ores are converted into oxides by roasting the ore in airD. Mercury cannot be produced by roasting the ore of cinnabar in air

Answer» Correct Answer - C
Roasting process is commonly used for sulphide ores.
47.

Aluminothermic process is used for the extraction of metals whose oxides are :A. fusibleB. not easily reduced by carbonC. not easily reduced by hydrogenD. strongly basic.

Answer» Correct Answer - B
Since the metal oxides have high melting points, their reduction by carbon is not satisfactory.
48.

Aluminothermic process is used for the extraction of metals, whose oxides areA. FusibleB. Not easily reduced by carbonC. Not easily reduced by hydrogenD. Strongly basic

Answer» Correct Answer - B
Aluminothermic process involvers reduction of oxides such
as `Fe_(2)O_(3),Mn_(3)O_(4),Cr_(2)O_(3)`etc. to metals with aluminum.
`Cr_(2)O_(3)+2A1_(2)O_(3) +2Cr DeltaH =- ve`
49.

Aluminothermic process is used for the extraction of metals, whose oxides areA. easily reduced by carbonB. not easily reduced by hydrogenC. fusibleD. strongly basic

Answer» Correct Answer - A
Aluminothermic process is used for the extraction of metals whose oxides are not easily reduced by carbon.
50.

 The close packed direction of a BCC crystal is (a) 〈1 1 1〉 (b) 〈1 1 0〉 (c) 〈1 0 0〉 (d) 〈1 0 1〉

Answer»

The close packed direction of a BCC crystal is  〈1 1 1〉