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.

What are the non – economic factors determining development?

Answer»

1. Human Resource 

2. Technical Know – how 

3. Political Freedom 

4. Social Organization 

5. Corruption free administration 

6. Desire for Development 

7. Moral, ethical and social values (viii) Casino Capitalism 

8. Patrimonial Capitalism

Non – Economic Factors: ‘Economic Development has much to do with human endowments, social attitudes, political conditions and historical accidents. Capital is a necessary but not a sufficient condition of progress.’

(I) Human Resources:

1. Human resource is named as human capital because of its power to increase productivity and thereby national income. 

2. There is a circular relationship between human development and economic growth. 

3. A healthy, educated and skilled labour force is the most important productive asset. 

4. Human capital formation is the process of increasing knowledge, skills and the productive capacity of people.

(II) Technical Know – how: As the scientific and technological knowledge advances, more and more sophisticated techniques steadily raise the productivity levels in all sectors.

(III) Political Freedom: The process of development is linked with the political freedom.

(IV) Social Organization: People show interest in the development activity only when they feel that the fruits of development will be fairly distributed.

(V) Corruption free administration:

1. Corruption is a negative factor in the growth process. 

2. Unless the countries root-out corruption in their administrative system, the crony capitalists and traders will continue to exploit national resources.

(VI) Desire for development: The pace of economic growth in any country depends to a great extent on people’s desire for development. 

(VII) Moral, ethical and social values:

1. These determine the efficiency of the market, according to Douglas C. North. 

2. If people are not honest, market cannot function.

(VIII) Casino Capitalism: If People spend larger propotion of their income and time on entertainment liquor and other illegal activities, productive activities may suffer, according to Thomas Piketty.

(IX) Patrimonial Capitalism: If the assets are simply passed on to children from their parents, the children would not work hard, because the children do not know the value of the assets.

2.

The four P's of the marketing mix are (a) personnel, priorities, placement, and profits. (b) promotion, product, personnel, and place. (c) product, place, politics and economy. (d) product, promotion, price and place.

Answer»

Correct option is (d) product, promotion, price and place.

3.

Critically explain Say’s law of market?

Answer»

Criticisms of Say’s Law: 

The following are the criticisms against Say’s law:

1. According to Keynes, supply does not create its demand. It is not applicable where demand does not increase as much as production increases

2. Automatic adjustment process will not remove unemployment. Unemployment can be removed by increase in the rate of investment. 

3. Money is not neutral. Individuals hold money for unforeseen contingencies while businessmen keep cash reserve for future activities.

4. Say’s law is based on the proposition that supply creates its own demand and there is no over production. Keynes said that over production is possible.

5. Keynes regards full employment as a special case because there is under – employment in capitalist economies. 

6. The need for state intervention arises in the case of general over production and mass unemployment.

4.

समान उद्देश्यों की प्राप्ति के रूप में कार्यरत व्यक्तियों के मध्य अधिकार और दायित्व का विभाजन करनेवाला ढाँचा अर्थात् ……………………(A) सूचना प्रेषण(B) नियंत्रण(C) व्यवस्थातंत्र(D) मार्गदर्शन

Answer»

सही विकल्प है (A) सूचना प्रेषण

5.

What is short-term finance?

Answer»

Short-term finance, usually, refers to finance required by a firm for a period of one year or less. It is the finance required for the purchase of raw materials, payment of wages and salaries and for meeting the other day – to -day manufacturing,-administrative, marketing and other expenses of a firm. It is called short-term finance, as it is required for a short period of one year or less.

6.

Mention the types of business finance.

Answer»

The business finance is classified into three types. 

1. Short – Term Finance 

2. Medium – Term Finance 

3. Long – Term Finance.

7.

What is cost of capital?

Answer»

When money is borrowed from banks or other financial institutions one needs to pay interest on it. The interest paid can be termed as the ‘cost of capital’.

8.

Fill in the blanks in each of the following:(i) C.P. = Rs 1265, S.P. = Rs 1253, Loss = Rs …….(ii) C.P. = Rs……., S.P. = Rs 450, Profit = Rs 150(iii) C.P. = Rs 3355, S.P. = Rs 7355,……. = Rs……(iv) C.P. = Rs……., S.P. = Rs 2390, Loss = Rs 5.50

Answer»

(i) Loss = Rs 12

Explanation:

Given CP = Rs. 1265, SP = Rs. 1253

Loss = CP – SP

= Rs. (1265 – 1253)

= Rs. 12

(ii) C.P. = Rs 300

Explanation:

Given CP = 7, SP = Rs. 450, profit = Rs. 150

Profit = SP – CP

150 = 450 – CP

CP = Rs. (450 – 150)

= Rs. 300

(iii) Profit = Rs 4000

Explanation:

Given CP = Rs. 3355, SP = Rs. 7355,

Here SP > CP, so profit.

Profit = SP – CP

Profit = Rs. (7355 – 3355)

= Rs. 4000

(iv) C. P. = Rs 2395.50

Explanation:

Given CP = 7, SP = Rs. 2390, loss = Rs. 5.50

Loss = CP – SP

5.50 = CP – 2390 CP

= Rs. (5.50 + 2390)

= Rs. 2395.50

9.

Calculate the profit or loss and profit or loss per cent in each of the following cases:(i) C.P. = Rs 4560, S.P. = Rs 5000(ii) C.P. = Rs 2600, S.P. = Rs 2470(iii) C.P. = Rs 332, S.P. = Rs 350(iv) C.P. = Rs 1500, S.P. = Rs 1500

Answer»

(i) Given CP = Rs. 4560, SP = Rs. 5000

Here, clearly SP > CP. So, profit.

Profit = SP – CP

= Rs. (5000 – 4560)

= Rs. 440

Profit % = {(Profit/CP) x 100} %

= {(440/4560) x 100} %

= {0.0965 x 100} %

Profit % = 9.65%

(ii) Given CP = Rs. 2600, SP = Rs. 2470.

Here, clearly CP > SP. So, loss.

Loss = CP – SP

= Rs. (2600 – 2470)

= Rs. 130

Loss % = {(Loss/CP) x 100} %

= {(130/2600) x 100} %

= {0.05 x 100} %

Loss % = 5%

(iii) Given CP = Rs. 332, SP= Rs. 350.

Here, clearly SP > CP. So, profit.

Profit = SP – CP

= Rs. (350 – 332)

= Rs. 18

Profit% = {(Profit/CP) x 100} %

= {(18/332) x 100} %

= {0.054 x 100} %

Profit % = 5.4%

(iv) Given CP = Rs. 1500, SP = Rs. 1500

Here clearly SP = CP.

So, neither profit nor loss.

10.

Verify Rolle’s Theorem for the function: f(x) = cos 2x in [0, π]

Answer»

We know that

(i) f (x) = cos 2x is a trigonometric function which is continuous

Hence, f (x) = cos 2x is continuous on [0, π]

(ii) f’(x) = – 2sin 2x exist in [0, π]

Hence, f (x) = cos 2x is differentiable on (0, π)

(iii) We know that

f (0) = cos 2(0) = 0

Similarly f (π) = cos 2(π) = 0

Here f (0) = f (π)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (0, π) where f’(c) = 0

– 2sin 2c = 0

Which gives 2c = π

We know that value of c = π/2 ϵ (0, π)

Therefore, Rolle’s Theorem is satisfied.

11.

Find the gain or loss per cent, when:(i) C.P. = Rs 4000 and gain = Rs 40.(ii) S.P. = Rs 1272 and loss = Rs 328(iii) S.P. = Rs 1820 and gain = Rs 420.

Answer»

(i) Given CP = Rs. 4000, gain = Rs. 40

Gain % = {(Gain/CP) x 100) %

= {(40/4000) x 100} %

= (0.01 x 100) %

Gain % = 1%

(ii) Given SP = Rs. 1272, loss = Rs. 328

Loss = CP – SP

Hence, CP = Loss+ SP

= Rs. 328 + Rs. 1272

= Rs. 1600

Loss % = {(Loss/CP) x 100} %

= {(328/1600) x 100%

Loss % = 20.5%

(iii) Given SP = Rs. 1820, gain = Rs. 420

Gain = SP – CP

CP = 1820 – 420

= Rs. 1400

Gain % = {(Gain/CP) x 100} %

= {(420/1400) x 100 %

Gain % = 30%

12.

A grain merchant sold 600 quintals of rice at a profit of 7%. If a quintal of rice cost him Rs 250 and his total overhead charges for transportation, etc. were Rs 1000 find his total profit and the selling price of 600 quintals of rice.

Answer»

Given Cost of 1 quintal of rice = Rs. 250

Cost of 600 quintals of rice = 600 x 250 = Rs. 150000

Overhead expenses = Rs. 1000

CP = Rs. (150000 + 1000) = Rs. 151000

Profit % = (Profit/CP) x 100

7 = (Profit /151000) x 100

Profit = 1510 x 7

Profit = Rs. 10570

Now SP = CP + profit

= Rs. (151000 + 10570)

SP = Rs. 161570

13.

Verify Rolle’s Theorem for the function: f(x) = cos x in [-π/2, π/2]

Answer»

We know that

(i) f (x) = cos x is a trigonometric function which is continuous

Hence, f (x) = cos x is continuous on [-π/2, π/2]

(ii) f’(x) = – sin x exist in [-π/2, π/2]

Hence, f (x) = cos x is differentiable on (-π/2, π/2)

(iii) We know that

f (-π/2) = cos (-π/2) = 0

Similarly f (π/2) = cos (π/2) = 0

Here f (-π/2) = f (π/2)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (-π/2, π/2) where f’(c) = 0

– sin c = 0

Which gives c = 0

We know that value of c = 0 ϵ (-π/2, π/2)

Therefore, Rolle’s Theorem is satisfied.

14.

Verify Rolle’s Theorem for the function: f(x) = (x – 2)4 (x – 3)3 in [2, 3]

Answer»

We know that

(i) f (x) = (x – 2)4 (x – 3)3 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = (x – 2)4 (x – 3)3 is continuous on [2, 3]

(ii) f’(x) = 4 (x – 2)3 (x – 3)3 + 3 (x – 2)4 (x – 3)2 exist in [2, 3]

Hence, f (x) = (x – 2)4 (x – 3)3 is differentiable on (2, 3)

(iii) We know that

f (2) = (2 – 2)4 (2 – 3)3 = 0

Similarly f (3) = (3 – 2)4 (3 – 3)3 = 0

Here f (2) = f (3)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (2, 3) where f’(c) = 0

So we get

4 (c – 2)3 (c – 3)3 + 3 (c – 2)4 (c – 3)2 = 0

We know that

(c – 2)3 (c – 3)2 (7c – 18) = 0

Which gives c = 2 or 3 or 18/7

We know that value of c = 18/7 ϵ (2, 3)

Therefore, Rolle’s Theorem is satisfied.

15.

Verify Rolle’s Theorem for the function: f(x) = (x – 1) (x – 2)2 in [1, 2]

Answer»

We know that

(i) f (x) = (x – 1) (x – 2)2 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = (x – 1) (x – 2)2 is continuous on [1, 2]

(ii) f’(x) = (x – 2)2 + 2 (x – 1) (x – 2) exist in [1, 2]

Hence, f (x) = (x – 1) (x – 2)2 is differentiable on (1, 2)

(iii) We know that

f (1) = (1 – 1) (1 – 2)2 = 0

Similarly f (2) = (2 – 1) (2 – 2)2 = 0

Here f (1) = f (2)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (1, 2) where f’(c) = 0

So we get

(c – 2)2 + 2 (c – 1) (c – 2) = 0

We know that

(3c – 4) (c – 2) = 0

Which gives c = 2 or 4/3

We know that value of c = 4/3 ϵ (1, 2)

Therefore, Rolle’s Theorem is satisfied.

16.

Verify Rolle’s theorem for each of the following functions:f(x) = x3 - 7x2+16x - 12 in [2, 3]

Answer»

Condition (1):

Since, f(x) = x- 7x2+16x -12 is a polynomial and we know every polynomial function is continuous for all x ϵ R.

⇒ f(x) = x- 7x2+16x -12 is continuous on [2,3].

Condition (2):

Here, f’(x) = 3x- 14x+16 which exist in [2,3].

So, f(x) = x- 7x2+16x -12 is differentiable on (2,3).

Condition (3):

Here, f(2) = 2- 7(2)2+16(2) -12 = 0

And f(3) = 3- 7(3)2+16(3) -12 = 0

i.e. f(2) = f(3)

Conditions of Rolle’s theorem are satisfied.

Hence, there exist at least one c ϵ (2,3) such that f’(c) = 0

i.e. 3c- 14c+16 = 0

i.e. (c - 2)(3c - 7) = 0

i.e. c = 2 or c = 7 ÷ 3

Value of c = 7/3 ϵ (2, 3)

Thus, Rolle’s theorem is satisfied.

17.

Verify Rolle’s Theorem for the function: f(x) = x3 + 3x2 – 24x – 80 in [- 4, 5]

Answer»

We know that

(i) f (x) = x3 + 3x2 – 24x – 80 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = x3 + 3x2 – 24x – 80 is continuous on [- 4, 5]

(ii) f’(x) = 3x2 + 6x – 24 exist in [- 4, 5]

Hence, f (x) = x3 + 3x2 – 24x – 80 is differentiable on (- 4, 5)

(iii) We know that

f (- 4) = (- 4)3 + 3 (4)2 – 24(4) – 80 = 0

Similarly f (5) = 53 + 3(5)2 – 24 (5) – 80 = 0

Here f (- 4) = f (5)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (- 4, 5) where f’(c) = 0

3c2 + 6c – 24 = 0

Which gives c = – 4 or 2

We know that value of c = 2 ϵ (- 4, 5)

Therefore, Rolle’s Theorem is satisfied.

18.

Verify Rolle’s Theorem for the function: f(x) = x2 – 3x – 18 in [-3, 6]

Answer»

We know that

(i) f(x) = x2 – 3x – 18 is a polynomial which is continuous for all x ϵ R

Hence, f(x) = x2 – 3x – 18 is continuous on [-3, 6]

(ii) f’(x) = 2x – 3 exist in [-3, 6]

Hence, f(x) = x2 – 3x – 18 is differentiable on (- 3, 6)

(iii) We know that

f(-3) = (-3)2 – 3(-3) – 18 = 0

Similarly f(6) = 62 – 5(6) – 18 = 0

Here f(-3) = f(6)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (- 3, 6) where f’(c) = 0

2c – 3 = 0 which gives c = 3/2

We know that value of c = 3/2 ϵ (-3, 6)

Therefore, Rolle’s Theorem is satisfied.

19.

Verify Rolle’s Theorem for the function: f(x) = x3 – 7x2 + 16x – 12 in [2, 3]

Answer»

We know that

(i) f (x) = x3 – 7x2 + 16x – 12 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = x3 – 7x2 + 16x – 12 is continuous on [2, 3]

(ii) f’(x) = 3x2 – 14x + 16 exist in [2, 3]

Hence, f (x) = x3 – 7x2 + 16x – 12 is differentiable on (2, 3)

(iii) We know that

f (2) = (2)3 – 7 (2)2 + 16(2) – 12 = 0

Similarly f (3) = 33 – 7(3)2 + 16 (3) – 12 = 0

Here f (2) = f(3)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (2, 3) where f’(c) = 0

3c2 – 14c + 16 = 0

It can be written as

(c – 2) (3c – 7) = 0 which gives c = 7/3

We know that value of c = 7/3 ϵ (2, 3)

Therefore, Rolle’s Theorem is satisfied.

20.

Verify Rolle’s Theorem for the function: f(x) = x(x – 4)2 in [0, 4]

Answer»

We know that

(i) f (x) = x (x – 4)2 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = x (x – 4)2 is continuous on [0, 4]

(ii) f’(x) = (x – 4)2 + 2x (x – 4) exist in [0, 4]

Hence, f (x) = x (x – 4)2 is differentiable on (0, 4)

(iii) We know that

f (0) = 0(0 – 4)2 = 0

Similarly f (4) = 4 (4 – 4)2 = 0

Here f (0) = f(4)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (0, 4) where f’(c) = 0

(c – 4)2 + 2c (c – 4) = 0

It can be written as

(c – 4) (3c – 4) = 0

Here c = 4 or c = 3/4

We know that value of c = 3/4 ϵ (0, 4)

Therefore, Rolle’s Theorem is satisfied.

21.

Verify Rolle’s Theorem for the function: f(x) = x2 – 4x + 3 in [1, 3]

Answer»

We know that

(i) f (x) = x2 – 4x + 3 is a polynomial which is continuous for all x ϵ R

Hence, f (x) = x2 – 4x + 3 is continuous on [1, 3]

(ii) f’(x) = 2x – 4 exist in [1, 3]

Hence, f (x) = x2 – 4x + 3 is differentiable on (1, 3)

(iii) We know that

f (1) = (1)2 – 4(1) + 3 = 0

Similarly f (3) = 32 – 4(3) + 3 = 0

Here f (1) = f(3)

The conditions of Rolle’s Theorem are satisfied.

There exist at least one c ϵ (1, 3) where f’(c) = 0

2c – 4 = 0 which gives c = 4/2 = 2

We know that value of c = 2 ϵ (1, 3)

Therefore, Rolle’s Theorem is satisfied.

22.

Verify Rolle’s theorem for each of the following functions:f(x) = x2 - x - 12 in [-3, 4]

Answer»

Condition (1):

Since, f(x) = x- x -12 is a polynomial and we know every polynomial function is continuous for all x ϵ R.

⇒ f(x) = x- x -12 is continuous on [-3,4].

Condition (2):

Here, f’(x) = 2x -1 which exist in [-3,4].

So, f(x) = x- x -12 is differentiable on (-3,4).

Condition (3):

Here, f(-3) = (-3)2 - 3 -12 = 0

And f(4) = 4- 4 -12 = 0

i.e. f(-3) = f(4)

Conditions of Rolle’s theorem are satisfied.

Hence, there exist at least one c ϵ (-3,4) such that f’(c) = 0

i.e. 2c-1 = 0

i.e. c = 1/2

Value of c = 1/2 ϵ (-3,4)

Thus, Rolle’s theorem is satisfied.

23.

Verify Rolle’s theorem for each of the following functions:f(x) = x2 on [-1, 1]

Answer»

Condition (1):

Since, f(x) = x2 is a polynomial and we know every polynomial function is continuous for all x ϵ R.

⇒ f(x) = x2 is continuous on [-1,1].

Condition (2):

Here, f’(x) = 2x which exist in [-1,1].

So, f(x) = x2 is differentiable on (-1,1).

Condition (3):

Here, f(-1) = (-1)2 = 1

And f(1) = 11 = 1

i.e. f(-1) = f(1)

Conditions of Rolle’s theorem are satisfied.

Hence, there exist at least one c ϵ (-1,1) such that f’(c) = 0

i.e. 2c = 0

i.e. c = 0

Value of c = 0 ϵ (-1,1)

Thus, Rolle’s theorem is satisfied.

24.

Verify Rolle’s theorem for each of the following functions:f(x) = x(x - 4)2 in [0, 4]

Answer»

Condition (1):

Since, f(x) = x(x - 4)2 is a polynomial and we know every polynomial function is continuous for all x ϵ R.

⇒ f(x) = x(x - 4)2 is continuous on [0,4].

Condition (2):

Here, f’(x) = (x - 4)2+2x(x - 4) which exist in [0,4].

So, f(x) = x(x - 4)2 is differentiable on (0,4).

Condition (3):

Here, f(0) = 0(0 - 4)2 = 0

And f(4) = 4(4 - 4)= 0

i.e. f(0) = f(4)

Conditions of Rolle’s theorem are satisfied.

Hence, there exist at least one c ϵ (0,4) such that f’(c) = 0

i.e. (c - 4)2+2c(c - 4) = 0

i.e. (c - 4)(3c - 4) = 0

i.e. c = 4 or c = 3 ÷ 4

Value of c = 3/4 ϵ (0, 4)

Thus, Rolle’s theorem is satisfied.

25.

If y = sin-1(3x - 4x3) then dy/dx = ?A. 3/√1-x2B. -4/√1-x2C. 3/√1+x2D. none of these

Answer»

Answer is: 3/√1-x2

Given that y = sin-1(3x - 4x3)

Let x = sin θ

⇒ θ = sin-1x

Then, y = sin-1(3sinθ - 4sin3θ)

Using sin3θ = 3sinθ - 4sin 3θ, we get

y = sin-1(sin3θ) = 3θ = 3sin-1x

Differentiating with respect to x, we get

dy/dx = 3/√1-x2

26.

Verify Rolle’s theorem for each of the following functions:f(x)  = x2 - 4x+3 in [1, 3]

Answer»

Condition (1):

Since, f(x) = x- 4x+3 is a polynomial and we know every polynomial function is continuous for all x ϵ R.

⇒ f(x) = x- 4x+3 is continuous on [1,3].

Condition (2):

Here, f’(x) = 2x - 4 which exist in [1,3].

So, f(x) = x- 4x+3 is differentiable on (1,3).

Condition (3):

Here, f(1) = (1)- 4(1)+3 = 0

And f(3) = (3)- 4(3)+3 = 0

i.e. f(1) = f(3)

Conditions of Rolle’s theorem are satisfied.

Hence, there exist at least one c ϵ (1,3) such that f’(c) = 0

i.e. 2c - 4 = 0

i.e. c = 2

Value of c = 2 ϵ (1,3)

Thus, Rolle’s theorem is satisfied.

27.

The following graph shows the temperature forecast and the actual temperature for each day of a week.(a) On which days was the forecast temperature the same as the actual temperature?(b) What was the maximum forecast temperature during the week?(c) What was the minimum actual temperature during the week?(d) On which day did the actual temperature differ the most from the forecast temperature?

Answer»

(a) The forecast temperature was same as the actual temperature on Tuesday, Friday, and Sunday.

(b) The maximum forecast temperature during the week was 35°C.

(c) The minimum actual temperature during the week was 15°C.

(d) The actual temperature differs the most from the forecast temperature on Thursday.

28.

A tank, which is open at the top, contains a liquid up to a height H. A small hole is made in the side of the tank at a distance y below the liquid surface. The liquid emerging from the hole lands at a distance x from the tank.(a) If y is increased from zero to H, x will first increase and then decrease.(b) x is maximum for y = H/2. (c) The maximum value of x is H. (d) The maximum value of x will depend on the density of the liquid.

Answer»

Correct Answer is: (a, b, & c)

The velocity of efflux = v = 2gy.

The emerging liquid moves as a projectile and reaches the ground in time t, where, 

H - y = 1/2 gt2 or  t =(2(H - y))/g

∴ x = vt= 2 (H - y)y.

For x to be maximum,dx/dy = 0 or y = H/2

∴ xmax = H. 

29.

Lichens are symbiotic association of A) Algae and bacteria B) Algae and fungi C) Bacteria and virus D) Fungi and bacteria

Answer»

B) Algae and fungi

30.

What were the two criteria used by Mendeleev in creating his Periodic Table?

Answer»

Increasing order of atomic mass and similarity in chemical properties i.e. the nature of oxide and hydride formed.

31.

Compare and contrast biomass and hydroelectricity as sources of energy.

Answer»

(i) Biomass is a renewable source of energy only if we plant trees in a planned manner which is not the case with hydroelectricity.
(ii) The energy from bio-mass can be obtained by using a chulha or a gobar gas plant whereas hydroelectricity requires construction of dams on rivers.
(iii) Biomass provides pollution-free energy only, when converted into bio-gas whereas hydroelectricity.
is totally pollution-fi'ee.

32.

What do you think about the stranger?

Answer»

The stranger seems to be very simple and foolish. He cannot understand Taffy’s body language and the non-verbal communication. He interprets Tegumai’s behavior too in the wrong manner. He seems to be in awe of Tegumai and Taffy, thinking that Tegumai is a haughty chief.

33.

The magnetic field along the axis of a circular coil is found to beB = \(\frac{\mu_0Ia^2}{2(r^2+a^2)^{3/2}}\)1. What is the magnetic field along the axis if r>>a 2.Compare the above magnetic field with the electric field along the axis of an electric dipoleWhat is the equation of magnetic dipole moment?

Answer»

1. B = \(\frac{\mu_0/a^2}{2r^3}\)

2.

  • Electric field due to electric dipole,

E = \(\frac{1}{4\pi ε_0}\frac{P}{r^3}\) magnetic field due to magnetic dipole

B = \(\frac{\mu_0}{4\pi}\frac{m}{x^3}\)

  • Magnetic moment m = IA
34.

Despite many obstacles. Helen still decided to appear for the examination. What was the impression created by Helen with this step?

Answer»

Helen looked forward to her second year at Gilman’s school. However, she was confronted with unexpected difficulties that year which caused her a great deal of frustration. She had to study mathematics without the needed tools. The classes were larger and it was not possible for the Cambridge teachers to give her special instructions. Anne Sullivan had to read all the books to her. Helen had to wait in order to buy a Braille writer so that she could do her algebra, geometry and physics. When the embossed books and the other apparatus arrived, Helen’s difficulties began to disappear and she began to study with confidence. However, Mr. Gilman thought that Helen was overworked and was breaking down. He insisted that she was overworked, and that she should remain at his school three years longer. He made changes in her studies. A difference of opinion between Mr. Gilman and Miss Sullivan resulted in Helen’s mother withdrawing Helen and Mildred from the Cambridge school. Helen went on to continue her studies under a tutor. Helen found it easier to study with a tutor than receive instructions in class. When Helen took her exam in June 1899, she faced many difficulties, as the administrative board of Radcliffe did not realize how difficult they were making her examinations. They did not understand the peculiar difficulties Helen had to go through. However, Helen, with her great and determination, overcame them all.

35.

The amount of energy radiated per unit time by a body does not depend upon the (A) nature of its surface (B) area of its surface (C) mass of the body (D) temperature difference of the surface and surroundings.

Answer»

Correct Option Is (C) mass of the body

\(\theta = \sigma AT^4\)

Where,

\(\theta = \) Energy Radiated

A = Area

T = Temperature

\(\sigma =\) Conductivity

(C) mass of the body

36.

The light from the Sun is found to have a maximum intensity near the wavelength of 470 nm. Assuming the surface of the Sun as a blackbody, the temperature of the Sun is [Wien’s constant b = 2.898 × 10-3 m.K] (A) 5800 K (B) 6050 K (C) 6166 K (D) 6500 K.

Answer»

Correct Option is (C) 6166 K

Given, \(\lambda m = 470 \ nm\)

T = ?

\(\lambda m T = b\)

\(T = \frac{b}{\lambda m}\)

\(T = \frac{2.898 \times 10^{-3}}{470 \ nm}\)

\(T = \frac{2.898 \times 10^{-3}}{470 \times 10^{-9}}\)

\(T = 0.0061659 \times 10^6\)

T = 6165 K

Correct option is (C) 6166 K

37.

The substance which allows heat radiations to pass through it is (A) iron (B) water vapour (C) wood (D) dry air.

Answer»

Correct option is (D) dry air.

38.

Which of the following materials is diathermanous ? (A) Wax (B) Glass (C) Quartz (D) Porcelain

Answer»

Correct option is (C) Quartz

39.

Which of the following substances is opaque to radiant energy? (A) Carbon tetrachloride (B) Sodium chloride (C) Benzene (D) Potassium bromide

Answer»

Correct Option is (C) Benzene

Benzene is a very stable hudrocarbon . Hence very opaque to radiant heat or thermal radiation.

Correct option is (C) Benzene

40.

The ratio of emissive power of a perfect blackbody at 1327°C and 527°C is(A) 4 : 1 (B) 16 : 1 (C) 2 : 1 (D) 8 : 1

Answer»

Correct answer is: (B) 16 : 1

41.

On what factors do the degrees of freedom depend?

Answer»

The degrees of freedom depend upon 

(i) the number of atoms forming a molecule 

(ii) the structure of the molecule 

(iii) the temperature of the gas.

42.

The mean free path λ of molecules is given by(A) \(\sqrt{\cfrac{2}{\pi nd^2}}\)(B) \(\cfrac{1}{\pi nd^2}\)(C) \(\cfrac{1}{\sqrt{2\pi nd^2}}\)(D) \(\cfrac{1}{\sqrt{2\pi nd^1}}\)where n is the number of molecules per unit volume and d is the diameter of the molecules.

Answer»

 Correct answer is: (C) \(\cfrac{1}{\sqrt{2\pi nd^2}}\)

43.

If a = 0.72 and r = 0.24, then the value of tr is(A) 0.02 (B) 0.04 (C) 0.4 (D) 0.2

Answer»

Correct answer is: (B) 0.04

44.

In an ideal gas, the molecules possess(A) only kinetic energy (B) both kinetic energy and potential energy (C) only potential energy (D) neither kinetic energy nor potential energy

Answer»

Correct answer is: (A) only kinetic energy

45.

For a certain body, the coefficient of absorption (absorptive power, absorptivity) is 0.4. The body is maintained at a constant temperature. The radiant power of a perfect blackbody maintained at the same temperature is 5 × 104 W/m2 . Find the radiant power of the body at that temperature.

Answer»

Data: a = 0.4, Rb = 5 × 104 W/m2

As the emissivity, e = a, 

we have, e = 0.4

∴ R = eRb = (0.4) (5 × 104 W/m2)

= 2 × 104 W/m2

This is the required quantity.

46.

If for a certain body, under certain conditions, the coefficient of absorption is 0.2 and the coefficient of reflection is 0.5, what will be the coefficient of transmission ?

Answer»

In the usual notation, a + r +1 = 1 

Hence, the coefficient of transmission of the body = 1 – (a + r) = 1 – (0.2 + 0.5) = 1 – 0.7 = 0.3.

47.

Name and define the modes of heat transfer.

Answer»

The three modes of heat transfer are conduction, convection and radiation.

1. Conduction is the mode of heat transfer within a body or between two bodies in contact, from a region of high temperature to a region of lower temperature without the migration of the particles of the medium.

2. Convection is the mode of heat transfer from one part of a fluid to another by the migration of the particles of the fluid. 

3. Radiation is the mode of heat transfer by electromagnetic waves / quanta.

48.

What is an ideal gas ? Does an ideal gas exist in practice ?

Answer»

An ideal or perfect gas is a gas which obeys the gas laws (Boyle’s law, Charles’ law and Gay-Lussac’s law) at all pressures and temperatures. An ideal gas cannot be liquefied by application of pressure or lowering the temperature.

A molecule of an ideal gas is an ideal particle having only mass and velocity. Its structure and size are ignored. Also, intermolecular forces are zero except during collisions

49.

Define athermanous substances and diathermanous substances.

Answer»

1. A substance which is largely opaque to thermal radiations, i.e., a substance which does not transmit heat radiations incident on it, is known as an athermanous substance.

2. A substance through which heat radiations can pass is known as a diathermanous substance.

50.

|(sin 30°,cos 30°),(-sin 60°,cos 60°)| = (a) 1(b) 0(c) 3/2(d) 1/2

Answer»

Answer is (a) 1