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.

Match List-I with List-IIList- IList-II(Hydrides)(Nature)(a) MgH2(i) Electron precise(b) GeH(ii) Electron deficient(c) B2H(iii) Electron rich(d) HF(iv) IonicChoose the correct answer from the options given below:(1) (a) (iii), (b)(i), (c) (ii), (d) (iv)(2) (a)-(i), (b) (ii), (c) - (iv), (d)- (iii)(3) (a)-(ii), (b) (iii), (c) - (iv), (d) (i)(4) (a) (iv), (b) (i), (c) (ii), (d) (iii)

Answer»

(4) (a) (iv), (b) (i), (c) (ii), (d) (iii)

Electron deficient hydride → Less than 8e (B2H6

Electron precise hydride → having 8e- without I.p. (GeH4

Electron rich hydride → having 8e- with 1.p. (HF)

2.

The incorrect statement regarding enzymes is:(1) Like chemical catalysts enzymes reduce the activation energy of bio processes.(2) Enzymes are polysaccharides.(3) Enzymes are very specific for a particular reaction and substrate.(4) Enzymes are biocatalysts.

Answer»

(2) Enzymes are polysaccharides.

Which is incorrect statement regarding enzymes 

(1) Like chemical catalysts enzymes reduce the activation energy of bio process ⇒ This is correct statement.

(2) Enzymes are polysaccharides ⇒ This is incorrect statement because enzymes are protein in nature 

(3) Enzymes are very specific for a particular reaction and substrate ⇒ This is correct statement. 

(4) Enzymes are biocatalyst ⇒This is correct statement.

3.

The incorrect statement regarding chirality is: (1) The product obtained by SN2 reaction of haloalkane having chirality at the reactive site shows inversion of configuration,(2) Enantiomers are superimposable mirror images of each other.(3) A racemic mixture shows zero optical rotation.(4) SN1 reaction yields 1 : 1 mixture of both enantiomers.

Answer»

(2) Enantiomers are superimposable mirror images of each other.

Enantiomers are non-superimposable mirror images of each other.

4.

1. The size of the air bubbles rising from the bottom of an aquarium increases. Can you explain the reason?2. What do you observe?3. What is the reason for the rising of the ink upwards?4. What did you observe on cooling the bottle after taking it out? Why?5. What can you infer about the relation between the volume and temperature of a gas?

Answer»

1. As the bubbles move upward, the pressure on them decreases. This causes increase in volume. So as the bubbles move upward, their size increases.

2. Ink rises through the tube

3. When the bottle is placed in hot water, air inside the bottle becomes hot. This causes expansion of air. This pushes ink in the tube. So ink rises through the tube.

4. Ink comes down. Because as air becomes cool, Its volume decreases.

5. When temperature is increased volume of gas increases. Similarly, when temperature is decreased, The volume decreases.

5.

The Bengal tiger, ______ can be seen in the local zoo, is an extremely interesting animal. A) of B) examples of which C) where D) of which

Answer»

Correct option is B) examples of which

6.

Choose the right order to make up a story.I. And Snickers are my favorite chocolate bars. II. The only problem is they make you fat. III. Sometimes it is difficult enough. IV. I like Snickers very much. V. That's why when I go past the sweet shop I always try to stop myself from going in. A) IV,III,V,II,I B) IV,I,II,V,III C) II,V,I,III,I D) IV,V,I,III,II E) I,III,V,IV,II

Answer»

Correct option is B) IV,I,II,V,III

7.

She’s spring-cleaning the house from bottom to top. The house ______ from top to bottom. A) is being spring-cleaned B) was to be spring-cleaned C) has been spring-cleaned D) is to be spring-cleaned

Answer»

Correct option is A) is being spring-cleaned

8.

They have used up all the petrol in the tank. All the petrol in the tank ______ up. A) has been using B) has been used C) will have been used D) have been used

Answer»

Correct option is B) has been used

9.

Why did Lakshmi leave the haveli ? लक्ष्मी ने हवेली को क्यों छोड़ दिया?

Answer»

Lakshmi was not satisfied with her husband Gangaram because he was ugly, poor and uncaring. Heera Lal, the driver took advantage of this situation and tried to entice Lakshmi. He gave her a blouse, a sari and a packet of delicious halwa. When Gangaram came to know about these gifts, he was furious. He bluntly abused her and ran to beat her. Lakshmi left the haveli in fear and humiliation.

लक्ष्मी अपने पति से सन्तुष्ट नहीं थी क्योंकि वह निर्धन, कुरूप तथा उसका ध्यान नहीं रखता। ड्राईवर हीरा लाल ने इस परिस्थिति का लाभ उठाया और लक्ष्मी को फांसने का प्रयास किया। उसने उसको ब्लाउज, सारी और लजीज हलवे का एक पैकेट दिया। जब गंगाराम को इन उपहारों के बारे में पता चला तो वह गुस्से से आग बबूला हो गया। उसने उसे बुरी तरह गालियाँ दी और उसे पीटने के लिये भागा। लक्ष्मी भय और अपमान से हवेली छोड़कर चली गई।

10.

Choose the right order to make up a story.1. In England this is an extremely interesting topic and you must be good at discussing it. 2. Perhaps, a long time ago when you wanted to describe someone as unusually dull, you used to say. 3. "He is the kind of person who always discusses the weather with you". 4. The weather is a very important topic in England. 5. Forget it. A) 4,1,2,5,3 B) 4,2,3,5,1 C) 4,5,2,1,3 D) 1,2,3,4,5 E) 4,3,2,1,5

Answer»

Correct option is B) 4,2,3,5,1

11.

The last days of the holiday ______ by rain. A) was spoiled B) are spoiled C) have been spoiled D) were spoiled

Answer»

Correct option is D) were spoiled

12.

Choose the right order to make up a story.I. I've been playing for several days now. II. I'm mad about computer games and can't live without them. III. Some computer games are very expensive. IV. I usually play for about two hours a day. V. That's why I can't buy the ones I want. A) V,I,IV,III,II B) II,IV,I,III,V C) III,V,I,II,IV D) II,I,III,IV,V E) I,II,V, IV, III

Answer»

Correct option is B) II,IV,I,III,V

13.

Choose the right order to make up a story.1. As it was almost a holiday event for the family we were in our best frocks. 2. You guessed right, the holiday was spoiled. 3. The day on which Daddy took us to the Zoo was a very bright and lovely Sunday. 4. Suddenly a car pushed past us, splashing us with dirty sprays of water from the nearest pool. 5. The Zoo being close to our house we walked there. 6. We had been looking forward to go there for the whole week. A) 1,2,3,4,5,6 B) 6,3,5,1,2,4 C) 5,6,4,2,3,1 D) 4,6,5,3,1,2 E) 3,6,1,5,4,2

Answer»

Correct option is E) 3,6,1,5,4,2

14.

“Geeta’s parents’ anxiety was not so much about her adjustment but whether she would be approved by Ajay’s parents.” Comment on the statement. गीता के माता-पिता की चिन्ता यह नहीं थी कि गीता उस परिवार के साथ कैसे सामंजस्य स्थापित करेगी किन्तु क्या अजय के माता-पिता उसे पसन्द करेंगे?” इस कथन की विवेचना कीजिए।

Answer»

The anxiety of Geeta’s parents was about Ajay’s family. The women of upper class family in Udaipur remained in purdah. They moved about with their face covered. But Geeta was a modern girl and had studied with boys. They believed that her education · would enable her to adjust herself to the new traditional family.But they thought that Ajay’s more orthodox relatives would not accept an educated modern girl.

गीता के माता-पिता की चिन्ता अजय के परिवार के विषय में थी। उदयपुर में उच्च जाति की महिलायें परदे में रहती थीं। वे अपना चेहरा ढककर ही इधर-उधर आती जाती थीं। परन्तु गीता एक आधुनिक लड़की थी और लड़कों के साथ पढ़ चुकी थी। उन्हें यकीन था कि उसकी शिक्षा उसे इस योग्य बना देगी कि वह परम्पराओं से बंधे परिवार के साथ सामंजस्य स्थापित कर लेगी। परन्तु वे सोचते थे कि अजय के कट्टर विचारधारा के रिश्तेदार एक सुशिक्षित लड़की को स्वीकार नहीं करेंगे।

15.

The only problem about sitting outside here in the evening is that you are likely to be ________ by mosquitoes. A) bitten B) grasped C) ground D) murdered E) picked

Answer»

Correct option is A) bitten

16.

Choose the right order to make up a story.I. We didn't know English and couldn't respond to his question. II. We took a trolley-bus to the Central Department Store. III. For the first time in my life I really regretted not having learned English at school properly. IV. My friend and I decided to go shopping. V. In the trolley-bus a foreigner addressed us in good English. A) I, III, II, VI, V B) II V, VI, III, I C) V, I, III, VI, II D) IV, III, I, II, V E) IV, II, V, I, III

Answer»

Correct option is E) IV, II, V, I, III

17.

What are the emotions that fill Geeta’s heart when she sees through lattice window in men’s apartment ? जब गीता संगमरमर की जाली वाली खिड़की से पुरुषों के कक्ष में देखती है तो उसके हृदय में क्या भाव उठते हैं?

Answer»

Seeing the splendour of the rooms, Geeta feels her heart filled with unusual joy. When she sees the portrait of her husband’s ancestors in their court-dress, she realizes that the people of the haveli are gentle, kind and brave. The emotions of joy, affection and pride fill her heart. She feels proud of being a bride of an honourable and royal family.

कमरे की शान शौकत देखकर गीता अपने हृदय को असाधारण आनन्द से भरा हुआ महसूस करती है। जब वह अपने पति के पूर्वजों की तसवीरें दरबारी पोशाक में देखती है तो वह समझ जाती है कि हवेली के लोग भले, दयालु और बहादुर हैं। खुशी, प्यार और गौरव की भावनायें उसके हृदय को भर देती हैं। एक सम्मानित और राजसी परिवार की वधू होने का उसे गर्व अनुभव होता है।

18.

I didn’t know his ________ so I couldn’t write to him. A) addressB) direction C) letter D) route E) way

Answer»

Correct option is A) address

19.

Benjamin Franklin ________ the lightning conductor. A) discovered B) found C) invented D) resulted E) solved

Answer»

Correct option is C) invented

20.

A thin rod of mass m has an angular velocity `omega_(0)` while rotating on a smooth surface. Determine its new angular velocity (in rads//s) just after its end strike and hooks onto the peg and the rod starts to rotate about P without rebounding. Solve the problem using the parameters given. `m=2kg, omega_(0)= rad//s, l=1.5 m`

Answer» Correct Answer - 1
(a) From conservation of angular momentum about P
`[(1)/(12)ml^(2)]omega_(0)=[(1)/(3)ml_(2)]omega`
`omega= (1)/(4)omega_(0)`
(b) From part (a) `omega=(1)/(4)omega_(0)=(1)/(4)(4)=1rad//s`
21.

A magnetic needle free to rotate in a vertical plane parallel to the magnetic meridian has its north tip pointing down at 22˚ with the horizontal. The horizontal component of the earth’ magnetic field at the place is known to be 0.35 G. Determine the strength of the earth’s magnetic field at the place.

Answer»

Here,

δ = 22˚, 

H = 0.35 G, 

R = ? 

As, 

H = R cosδ 

⇒ R = \(\frac{H}{cosδ}\) 

= \(\frac{0.35}{cos22°}\)

= \(\frac{0.35}{0.9272}\)

= 0.38 G

22.

Statement-1 : When two conducting wires of different resistivity have same cross sectional area are joined in series, the electric field in them would be equal when they carry current.Statement-2 : When wires are in series they carry equal current.(1)  Statement -1 is True, Statement -2 is True ; Statement -2 is a correct explanation for Statement -1(2) Statement-1 is true, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1(3) Statement-1 is true(4) Statement-1 is False, Statement-2 is True

Answer»

Correct option Statement-1 is False, Statement-2 is True

23.

The heating element of an electric heater should be made with a material which should have(a) High specific resistance and high melting point(b) High specific resistance and low melting point(c) Low specific resistance and high melting point(d) Low specific resistance and low melting point

Answer»

Correct option(a)

Explanation:

Heating element of an electric heater must be made with a material having high melting point so that it couldn’t melt easily and high specific resistance.

24.

 A 100 W bulb is connected in series with a room heater of 750 W. What will happen if the bulb is replaced by a 60W bulb? (A) Heater output will increase (B) Heater output will decrease (C) Heater output will remain unchanged (D) Bulb will not glow.

Answer»

(B) Heater output will decrease 

25.

A neutron makes a head on elastic collision with a stationary deuteron . The fractional energy neutron in the collision is(1) 16/18(2) 8/9(3) 8/27 (4) 2/3

Answer»

Answer is (2) 8/9

 ν1 = (m1 - m2)/(m1 + m2)u1 = [(m - 2m)/(m + 2m)]u = -u/3

Ei = (1/2) mu2, Ef = (1/2) m(-u/3)2 = 1/9 x (1/2) mu2.

(Ei – Ef)/Ei

= {1 – (1/9)}/1 = 8/9. 

26.

A + B →C + D ; ΔH = – 10,000 J mol–1 ,   ΔS = – 33.3 J mol–1 K–1(i) At what temperature the reaction will occur spontaneously from left to right ? (ii) At what temperature, the reaction will reverse?

Answer»

ΔG = ΔH – TΔS 

At equilibriu, ΔG = 0 so that ΔH = TΔS or

T = ΔH/ΔS = -1000 mol-1/-33.3JK-1 mol-1 = 300.03 K

(i) For spontaneity from left to right. G should be –ve for the given reaction. This will be so if T < 300.3 K 

(ii) For reverse reaction to occur, G should be +ve forward reaction. This will be so if T > 300.3 K.

27.

If `a, b, c` are distinct odd integers and `omega` is non real cube root of unity, then minimum value of `| a omega^2 + b+ comega|`, isA. `0`B. `3`C. `1`D. `2sqrt(3)`

Answer» Correct Answer - D
`|aomega^(2)+b+comega|^(2)`
`=1/2((a-b)^(2)+(b-c)^(2)+(c-a)^(2))`
`ge1/2(4+4+5)=12`
28.

The half life of a radioactive sample 38Sr90 is 2 years. Calculate the rate of disintegration of 15 mg of this isotope. Given Avogadro number = 6.023 x 1023.

Answer»

T1/2 = 28 years = 28 x 365 x 24 x 600 = 8.83 x 108 seconds 

90g \(Sr_{38}^{90}\) contains 6.023 x 1023 atoms 

λ = \(\frac{0.693}{T_{1/2}}\)

Decay constant λ = 7.85 x 1010 x 1.004 x 1.004 × 1010 

Rate of disintegration R= λN 

R = 7.88 x 1010 Bq

29.

A 20 Ω resistor; 1.5 H inductor and 35 μF capacitor are connected in series with a 220 V, 50 Hz ac supply, calculate the impedance of the circuit and also find the current through the circuit.

Answer»

R = 20Ω, L = 1.5 H, C = 35 x 10–6F, 

V = 220V, v = 50Hz, Z = ?, I = ?

Z = \(\sqrt{R^2+(X_c-X_L)^2}\)

XL = wL = 2πvL = 471 Ω

\(X_C = \frac{1}{\omega c}\) = \(\frac{1}{2\pi \theta c}\) = 90.99Ω

Calculation of Z = 380.53 Ω

I = \(\frac{v}{x}\) = 0.578 A

30.

Two vectors of equal magnitude 5 unit have an angle `60^0` between them. Find the magnitude of a the sum of the vectors and b the difference of the vectors. . .

Answer» ure shows the construction of the sum
` vecA+vecB` and the differece `vecA-vecB`.
`a vecA+vecB` is the sum to `vecA and vecB`. Both have a magnitude of unit nd the angle between them is `60^0`. Thus, the magnitude of the sum is
`|vecA+vecB|=sqrt(5^2+5^2+2xx5x5cos60^0)`
`=2xx5 cos 30^0=5sqrt 3` unit.
b. ` vecA-vecB` is the sum of `vecA and (-vecB)`. As shown in the ure, angle between `vecA and (-vecB)` is `120^0`. The magnitude of both `vecA and (-vecB)` is 5 unit so,
`|vecA-vecB|=sqrt95^2+5^2+2x5xx5 cos 120^0)`
1 = 2xx cos6060 = 5 unit`.
31.

A force of 10.5 N acts on a particle along a direction making an angle of `37^0` with the vertical. Find the component of the force in the vertical direction.

Answer» The component of the force in the vertical directiionwill be
`F_ _|_= F cos theta =(10.5N)(cos37^0)`
`=(10.5N) 4/5 =8.40N`
We can easily add two or more vectors if we know their components along the rectangular cordiN/Ate xes. Let us have
` veca=a_x veci+a_yvecj+a_2veck`
`vecb=b_x veci+b_yvecj+b_zveck`
`vecc=c_xveci+c_yvecj+c_2veck`
then
`veca+vecb+vecc=(a_x+b_x+c_x)veci+(a_y+by+c_y)vecj+(a_z+b_z+c_z)veck`.
If all the vectors are in the X-Y plane then all the z components are zero and the resultant is simply
`veca+vecb+vecc=(a_x+b_x+c_x) veci+(a_y+b_y+c_y)vecj`
This is the sum of twomutually perpendicular vectors of magnitude `(a_x+b_x+c_x) and (a_y+b_y+c_y)`. The resutant can easily be found to hae a magnitude
`sqrt((a_x+b_x+c_x)^2+(a_y+b_y+c_y)^2)`
making an angle alpha with the X-axis whre
`tan alpha= (a_y+b_y+c_y)/(a_x+b_x+c_x)`
32.

For a sequence `{a_(n)}, a_(1) = 2` and `(a_(n+1))/(a_(n)) = 1/3`, Then `sum_(r=1)^(oo) a_(r)` isA. `2//3`B. `3`C. `3//2`D. prime number

Answer» Correct Answer - A
33.

Let n quantities be in A.P., d being the common difference. Let the arithmetic mean of the squares of these quantities exceed the square of the arithmetic mean of these quantities by a quantity p. Then pA. is always negativeB. equals `(n^(2)- 1)/(12) d^(2)`C. equal s`(d^(2))/(12)`D. equals `(n^(2) - 1)/(12)`

Answer» Correct Answer - A
34.

The prime factorisation of 3825 is(a) 3x52 x 21(b) 32 x52 x 35(c) 32 x52 x 17(d) 32 x25 x 17

Answer»

Correct answer is: (c) 32 x52 x17

3825=32 x52 x17

35.

Learn Factorisation Methods Formulas and Rules for Algebraic Expressions Class 8 here.

Answer»

Factors:

We are aware that a natural number can be expressed as the product of other natural numbers. As
20 = 2 x 10 = 4 x 5
Thus, 1, 2, 4, 5, 10, 20 are the factors of 20. Of these 2 and 5 are prime factors of 20.

Similarly, there are factors of algebraic expressions as,
5ab = 5 x a x b where 5, a and b are prime factors of 5ab.

Factorisation:

When we factorise an algebraic expression, we write it as a product of factors. These factors may be numbers, algebraic variables or algebraic expressions.

Example: 12xy is already in factors but we write it as 3 x 2 x 2 x X x Y. thus factors are 2, 3, x, y.

Factorisation by Common Factors:

As the term common itself suggest that it must be some similar pattern.

A systematic way of factorising an expression is the common factor method. It consists of three steps:

  • Write each term of the expression as a product of irreducible factors
  • Look for and separate the common factors and
  • Combine the remaining factors in each term in accordance with the distributive law.

As example: We have to factorise 3x + 9.
first let’s factorise 3x = 3 x X and 9 = 3 x 3
similar pattern (say common) among these factors of both are 3
thus we can write 3x + 9 = 3 x X + 3 x 3 = 3(x + 3)

Factorisation by regrouping terms:

Rearranging the expression allows us to form groups leading to factorisation. This is regrouping.

Let us write (2xy + 2y) in the factor form:
2xy + 2y = (2 × x × y) + (2 × y)
= (2 × y × x) + (2 × y × 1)
= (2y × x) + (2y × 1) = 2y (x + 1)

Factorisation using identities:

  • (a + b)2 = a2 + 2ab + b2
  • (a – b)2 = a2 – 2ab + b2
  • (a + b) (a – b) = a2 – b2

Factors of the product form

  • (x + a).(x + b) = x2 + (a + b) x + ab

Division:

We already know that division is the inverse of multiplication for numerals. It is also applicable to the division of algebraic expressions.

Division of a monomial by another monomial:

We use the simple method for division. The division of numerical is same as we divide but for the monomials, we simply subtract the power of denominator from the numerator.

Example: \(\frac{21x^{4}}{7x}\) = 3x2

Division of Algebraic Expressions Continued (Polynomial ÷ Polynomial):

By taking the common factor we divide it.
Just an example: (7x2 + 14x) ÷ (x + 2)
(7x2 + 14x) = (7 × x × x) + (2 × 7 × x) = 7x(x + 2)
thus, (7x2 + 14x) ÷ (x + 2)
= \(\frac{7x(x + 2)}{x + 2}\) = 7x

Examples related to factorisation:

  1. Factorise 12a2b + 15ab2.
    Solution:
    As, 12a2b = 2 × 2 × 3 × a × a × b
    and, 15ab2 = 3 × 5 × a × b × b
    by seeing the two terms we find that these two terms have 3, a and b as common factors.
    12a2b + 15ab2 = (3 × a × b × 2 × 2 × a) + (3 × a × b × 5 × b)
    = 3 × a × b × [(2 × 2 × a) + (5 × b)]
    = 3ab × (4a + 5b)
    = 3ab (4a + 5b)
  2. Factorise 6xy – 4y + 6 – 9x.
    Solution:

    6xy – 4y = 2y (3x – 2)
    –9x + 6 = –3 (3x) + 3 (2)
    Taking them together,
    6xy – 4y + 6 – 9x = 6xy – 4y – 9x + 6
    = 2y (3x – 2) – 3 (3x – 2)
    = (3x – 2) (2y – 3)
    thus factors of (6xy – 4y + 6 – 9 x) are (3x – 2) and (2y – 3).
36.

Study here all Integral formulas, Indefinite integral formulas, Definite integral formulas here to clear the concept easily.

Answer»

Introduction to Integral formulas:

The list of integral calculus formula is here with all the rules which are needed to solve integration. The formula sheet of integration include basic integral formulas, integration by parts and partial fraction, area as a sum and properties of definite integral. At first take a look at indefinite integration.

Indefinite integral formulas:

  • Integration is the inverses of differentiation.
  • Two indefinite integrals having same derivative lead to the same family of curves, this makes them equivalent.
  • Addition rule of integration: ∫ [ f(x) + g(x) ]dx = ∫f(x) dx + ∫g(x) dx
  • The multiplication rule for any real number k, ∫k f(x) dx = k ∫f(x) dx
  1. \(\large \int  \; dx = x + C\)
  2. \(\large \int a \; dx = ax + C\)
  3. \(\large \int x^{n} \; dx = \frac{x^{n+1}}{n+1} + C; \; n \neq -1\)
  4. \(\large \int x^{n} \; dx = \frac{x^{n+1}}{n+1} + C; \; n \neq -1\)

Integral formulas of trigonometric functions:

∫ sin x dx = -cos x + c

∫ cos x dx = sin x + c

∫ tan x dx = log|sec x| + c

∫ cot x dx = log|sin x| + c

∫ sec x dx = log|sec x + tan x| + c

∫ cosec x dx = log|cosec x – cot x| + c

∫ sec2x dx = tan x + c

∫ cosec2x dx = -cot x + c

∫ sec x tan x dx = sec x + c

∫ cosec x cot x dx = - cosec x + c

Integral formulas for inverse trigonometric functions:

 \(\large \int \frac{1}{\sqrt{1-x^{2}}} \; dx = \sin^{-1} x + C\)

\(\large \int \frac{1}{\sqrt{1+x^{2}}} \; dx = \tan^{-1} x + C\)

\(\large \int \frac{1}{|x|\sqrt{x^{2}-1}} \; dx = \sec^{-1} x + C\)

\(\large \int \frac{dx}{\sqrt{x^{2}+ {a}^2}} \; dx = \frac{1}{a}\;{tan}^{-1} \frac{x}{a} + C\)

\(\large \int \frac{dx}{\sqrt{a^{2}- {x}^2}} \; dx = {sin}^{-1} \frac{x}{a} + C\)

∫ sin-1x dx = x sin-1x + \(\sqrt{1-{x}^2}\) + c

∫ cos-1x dx = x cos-1x - \(\sqrt{1-{x}^2}\) + c

∫ tan-1x dx = x tan-1x – ln\(\sqrt{1 + {x}^2}\) + c

∫ cot-1x dx = x cot-1x +ln\(\sqrt{1 + {x}^2}\) + c

∫ sec-1x dx = x sec-1x – ln|x + \(\sqrt{|{x}^2-1|}\)| + c

∫ cosec-1x dx = x cosec-1x + ln|x + \(\sqrt{|{x}^2-1|}\)| + c

Integral formulas for exponential trigonometric functions:

\(\large \int \sin^{n} (x) dx = \frac{-1}{n} \sin^{n-1} (x) \cos (x) +\frac{n-1}{n} \int \sin^{n-2} (x) dx\)

\(\large \int \cos^{n} (x) dx = \frac{1}{n} \cos^{n-1} (x) \sin (x) +\frac{n-1}{n} \int \cos^{n-2} (x) dx\)

\(\large \int \tan^{n} (x) dx = \frac{1}{n-1} \tan^{n-1} (x) +\int \tan^{n-2} (x) dx\)

\(\large \int \sec^{n} (x) dx = \frac{1}{n-1} \sec^{n-2} (x) \tan (x) + \frac{n-2}{n-1} \int \sec^{n-2} (x) dx\)

\(\large \int \csc^{n} (x) dx = \frac{-1}{n-1} \csc^{n-2} (x) \cot (x) + \frac{n-2}{n-1} \int \csc^{n-2} (x) dx\)

∫ sin2x dx = \(\frac{1}{2}\)x - \(\frac{1}{4}\)sin 2x + c

∫ cos2x dx = \(\frac{1}{2}\)x + \(\frac{1}{4}\)sin 2x + c

∫ tan2x dx = tan x – x + c

∫ cot2x dx = -cot x – x + c

Integral formulas for logarithmic functions:

∫ ax dx = \(\frac{{a}^x}{log\:a}\) + c

∫ \(\frac{1}{x}\) dx = log|x| + c

∫ \(\frac{dx}{{x}^2 –{a}^2}\) =\(\frac{1}{2a}\) log|\(\frac{x\:-\:a}{x\:+\:a}\)| + c

∫\(\frac{dx}{{a}^2 –{x}^2}\) = \(\frac{1}{2a}\) log|\(\frac{a\:+\:x}{a\:-\:x}\)| + c

∫\(\frac{dx}{\sqrt{{x}^2 –{a}^2}}\) = log |x + \(\sqrt{{x}^2 – {a}^2}\)| + c

∫\(\frac{dx}{\sqrt{{x}^2 +{a}^2}}\) = log |x + \(\sqrt{{x}^2 + {a}^2}\)| + c

Integral formulas for partial fractions:

\(\frac{px\:+\:q}{(x-a)(x-b)}\) = \(\frac{A}{x\:-\:a} + \frac{B}{x\:-\:b}\) , a ≠ b

\(\frac{px\:+\:q}{(x-a)^{2}}\) = \(\frac{A}{x\:-\:a} + \frac{B}{(x-a)^{2}}\)

\(\frac{p{x}^2+qx+r}{(x-a)(x-b)(x-c)}\) = \(\frac{A}{x\:-\:a} + \frac{B}{x\:-\:b} + \frac{C}{x\:-\:c}\)

\(\frac{p{x}^2+qx+r}{(x-a)^{2}(x-b)}\) = \(\frac{A}{x\:-\:a} + \frac{B}{(x-a)^{2}} + \frac{C}{x-b}\)

\(\frac{p{x}^2+qx+r}{(x-a) ({x}^2 + bx +c)}\) = \(\frac{A}{x-a} + {Bx+C}{{x}^2 + bx +c}\)

Where x2 +bx +c can’t be factorized further.

Integral Formulas by parts:

$$\large \int u\;v\;dx=u\int v\;dx-\int\left(\frac{du}{dx}\int v\;dx\right)dx$$

In this formula there is simple rule to know first and 2nd function i.e. u and v:

I - Inverse Function

L - Logarithmic Function

A – Algebraic Function

T- Trigonometric Function

E- Exponential Function

∫ ex [f(x) + f’(x)] dx = ∫ex f(x) dx + c

Some Special integral formulas:

∫ \(\sqrt{{x}^2 – {a}^2}\) dx = \(\frac{x}{2}\;\sqrt{{x}^2 – {a}^2}\) - \(\frac{{a}^2}{2}\)log|x + \(\sqrt{{x}^2 – {a}^2}\)| + c

∫\(\sqrt{{x}^2 + {a}^2}\) dx = \(\frac{x}{2}\;\sqrt{{x}^2 + {a}^2}\) + \(\frac{{a}^2}{2}\)log|x + \(\sqrt{{x}^2 + {a}^2}\)| + c

∫\(\sqrt{{a}^2 - {x}^2}\) dx = \(\frac{x}{2}\;\sqrt{{x}^2 – {a}^2}\) + \(\frac{{a}^2}{2}\) sin-1\(\frac{x}{a}\) + c

Definite integral formulas:

Actual Rule:

$$\large \int_{a}^{\infty}f(x)dx=\lim_{b\rightarrow \infty}\left [ \int_{a}^{b}f(x)dx\right ]$$

Or we can write:

$$\large \int_{a}^{b}f(x)dx=F(b)-F(a)$$

Here a is lower limit and b, ∞ are upper limits.

Some rational formula for definite integration:

\(\large \int_{a}^{\infty }\frac{dx}{x^{2}+a^{2}}=\frac{\pi }{2a}\)

\(\large \int_{a}^{\infty }\frac{x^{m}dx}{x^{n}+a^{n}}=\frac{\pi a^{m-n+1}}{n\sin \left ( \frac{(m+1)\pi }{n} \right )},0< m+1< n\)\)

\(\large \int_{a}^{\infty }\frac{x^{p-1}dx}{1+x}=\frac{\pi }{\sin (p\pi )},0< p< 1\)

\(\large \int_{a}^{\infty }\frac{x^{m}dx}{1+2x\cos \beta +x^{2}}=\frac{\pi \sin (m\beta )}{\sin (m\pi )\sin \beta }\)

\(\large \int_{a}^{\infty }\frac{dx}{\sqrt{a^{2}-x^{2}}}=\frac{\pi }{2}\)

\(\large \int_{a}^{\infty }\sqrt{a^{2}-x^{2}}dx=\frac{\pi a^{2}}{4}\)

Definite integration formula for trigonometric functions:

\(\large \int_{0}^{\pi }\sin(mx)\sin (nx)dx=\left\{\begin{matrix} 0 & if\;m\neq n\\ \frac{\pi }{2} & if\;m=n \end{matrix}\right.\;m,n\;positive\;integers\)

\(\large \int_{0}^{\pi }\cos (mx)\cos (nx)dx=\left\{\begin{matrix} 0 & if\;m\neq n\\ \frac{\pi }{2} & if\;m=n \end{matrix}\right.\;m,n\;positive\;integers\)

\(\large \int_{0}^{\pi }\sin (mx)\cos (nx)dx=\left\{\begin{matrix} 0 & if\;m+n\;even\\ \frac{2m}{m^{2}-n^{2}} & if\;m+n\;odd \end{matrix}\right.\;m,n\;integers\)

37.

Learn Maths Algebraic Formula, Exponents and Powers for Class 7 and Class 8 and Become experts in Algebra.

Answer»

Algebra Formula:

Do you ever think that if algebra were not there then how the mathematics would be? It would be like a human without a heart. Some of you think that it must be quiet interesting as we dont had to learn the algebra formula (jokes apart). For them, we have made it easy learning the formulas. In mathematics, algebra formula has a great use every time. we have made a list and PDF of algebra formula to ensure you better with the algebraic section.

Each formula which you need in solving Algebraic equation is listed here. Algebra formulas list for class 8, 9, 10, 11 & 12 will also help you in all competitive examinations like SSC, Railway, CBSE board etc. You must know that basic algebraic identities is in CBSE class 8 syllabus. Take a look at the algebra formula list below:


  • Square algebra formula

(a + b)2 = a2 + 2ab + b2

(a – b)2 = a2 – 2ab + b2

a2 – b2 = (a – b)(a + b)

a2 + b2 = (a – b)2 + 2ab = (a + b)2 – 2ab

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2ac + 2bc

(a – b – c)2 = a2 + b2 + c2 – 2ab – 2ac + 2bc

(a + b + c + …)2 = a2 + b2 + c2 + … + 2(ab + ac + bc + …..)


  • Cube based formula:

(a + b)3 = a3 + b3 + 3ab(a + b) ; (a + b)3 = a3 + 3a2b + 3ab2 + b3

(a – b)3 = a3 – 3a2b + 3ab2 – b3

a3 – b3 = (a – b)(a2 + ab + b2)

a3 + b3 = (a + b)(a2 – ab + b2)

(a + b)3 = a3 + 3a2b + 3ab2 + b3

(a – b)3 = a3 – 3a2b + 3ab2 – b3

(a + b + c)


  • 4th power algebra formula:

(a + b)4 = a4 + 4a3b + 6a2b2 + 4ab3 + b4)

(a – b)4 = a4 – 4a3b + 6a2b2 – 4ab3 + b4)

a4 – b4 = (a – b)(a + b)(a2 + b2)


  • 5th power formula:

a5 – b5 = (a – b)(a4 + a3b + a2b2 + ab3 + b4)


  • nth power algebra formula

If n is a natural number, an – bn = (a – b)(an-1 + an-2b+.…+ bn-2a + bn-1)

If n is even (n = 2k), an + bn = (a + b)(an-1 – an-2b +….+ bn-2a – bn-1)

If n is odd (n = 2k + 1), an + bn = (a + b)(an-1 – an-2b +….- bn-2a + bn-1)

(a + b + c + …)2 = a2 + b2 + c2 + … + 2(ab + ac + bc + …..)


  • Laws of Exponents (algebra formula)

(pm)(pn) = pm+n

(pq)m = pmqm

(pm)n = pmn


  • Fractional exponents:

$$a^{0}={1}$$

$$\frac{a^{m}}{a^{n}} = a^{m-n}{(if m>n)}$$

$$={1 (if m=n)}$$

$$=\frac{1}{a^{n-m}} {(if m<n)}$$

$$p^{m}= \frac{1}{a^{-m}}$$

$$a^{-m}=\frac{1}{a^{m}}$$


Those who want to solve questions then they can download algebra formula in pdf format. You can download it and learn it easily whenever & wherever you want.

Download Algebra formula PDF:

Algebra formula PDF Chart is available here to download. From the link provided below you can download Algebraic formula, equations pdf. The light pdf here includes all the formula from class 6 to class 12th. Take a look at it.

Algebra Formula PDF Download


  • Solved examples on algebra formula:

Q. Sove the question 152-52.

Solution:

As, a2 – b2 = (a – b)(a + b)

So,
152-5= (15-5)(15+5)
= (10)(20)
=200

Q. Sove the question 5x 54.

By using exponential equation (pm)(pn) = pm+n
so, 52x5= 56 = 78125

Q.Find the square of 4x+y.

As, (a + b)2 = a2 + 2ab + b2
(4x+y)2= (4x)+ 2(4xy) + (y)2
= 16x2+ 8xy + y2

Q.Express 16x2+24xy +9yas a perfect square.

Solution:

16x2+20xy +16y2
=(4x)2+ 2.4x.3y + (3y)2
= (4x + 3y)2

38.

Number system

Answer»

A number system is a collection of various symbols which are called digits.

39.

If `A = {1,2,3}, B = {3,4} , C = {4,5,6}`, then number of elements in the set `(AxxB)nn(BxxC)` is equal toA. 1B. 2C. 3D. 0

Answer» Correct Answer - A
If `A = {1,2,3}`, ……….
`AxxB= {(1,3), (1,4), (2,3), (2,4), (3,3), (3,4)}`
`BxxC= {(3,4), (3,5), (3,6), (4,4), (4,5), (4,6)}`
`(AxxB)nn(BxxC)= {(3,4)}`
40.

If `12^(4+2x^(2)) = (24sqrt(3))^(3x^(2)-2)`, then x is equal toA. `+- sqrt((13)/(12))`B. `+- sqrt((14)/(5))`C. `+- ((12)/(13))`D. `+- sqrt((5)/(14))`

Answer» Correct Answer - B
If `12^(4+2x^(2) = (24sqrt(3))^(3x^(2)-2)` ……….
Given `12^(4+2x^(2)) = (24sqrt(3))^(3x^(2)-2)`
`implies 12^(4+2x^(2))= (12)^((3)/(2)(3x^(2)-2))`
`implies 4+2x^(2) = (3)/(2) (3x^(2)-2) implies 8+4x^(2)=9x^(2)-6`
`implies 5x^(2) = 14 implies x = += sqrt((14)/(5))`
41.

Write a paragraph (150 words) by developing the following hints.Jack and Jill – call their house – a little nest – like birds make their nests – all collected free of cost – Jack and Jill – made their nest – right from villa – bought in instalment – take years to own.

Answer»

The Never Never Nest is a comic one-act play about a young couple who make full use of the buy-now-pay-later system. Jack and Jill were a young married couple who had a small baby. One day Aunt Jane visited them and was surprised to find that even though Jack’s salary was not high, they lived in a beautiful house with all comforts. She began to wonder whether, as a wedding gift she had given them 2000 pounds instead of 20 pounds. Otherwise how did Jack and Jill buy all these things? Then Jane understood that though they had everything, nothing really belonged to them. They bought everything on instalments.

Only a steering wheel of the car, a wheel and two cylinders had been paid for. The total amount to be paid towards instalments was more than their earnings. Aunt Jane was shocked at the way Jack and Jill ran their family. Before she left, she gave ten pounds to Jill and told them to make at least one article completely theirs, using that money. While Jack went with aunt Jane to the bus stop, Jill sent the money to Dr. Martin. Jack came back and said that he wanted to pay .two months instalments on the car using the aunt’s gift. But Jill said that by paying this money to Dr. Martin, their baby would become completely theirs.

42.

I ________ meet her every day. A) used to B) wanted C) liked D) am not able

Answer»

Correct option is A) used to

43.

Write a summary or make notes of the following passage.The word procrastination comes from two Latin terms meaning to ‘put forward until tomorrow’. Standard dictionary definitions include the idea of postponement or delay. Steel, a psychologist who has reviewed hundreds of studies on the subject, states that to procrastinate is “to voluntarily delay an intended course of action despite expecting to be worse-off for the delay”.Another expert, Dr. Joseph R. Ferrari, distinguishes between people who tend to put things off and “chronic” or “real” procrastinators for whom this is their life and who might even need therapy. Ferrari categorizes procrastinators into three types: (a) stimulation types that get a thrill from beating a deadline,(b) avoiders put off doing things that might make others think badly of them, and (c) decisional procrastinators who postpone making a decision until they have enough information to avoid making a wrong choice.Chronic procrastinators tend to have low selfesteem and focus on the past more than the future. The Discounted Expectancy Theory illustrates with a student like Sam who puts off writing a paper. When the deadline is far off, the rewards for socializing now are greater than those for finishing a task not due until later. As the deadline looms, the rewards or consequences for finishing the paper becomes more important.Tice and Baumeister found that procrastinators on the average got lower grades and had higher levels of stress and illness. Chu and Choi however, say that not all procrastinators are lazy and undisciplined. “Passive procrastinators” are more stressed and so less efficient. “Active procrastinators prefer to work under pressure” and “if something unexpectedly comes up, they will knowingly switch gears and engage in new tasks they perceive as more urgent.”

Answer»

Summary

No. of words given in the original passage: 280 No. of words to be written in the summary: 280/3 = 93 ± 5

Rough Draft

procrastination is a Latin word. Hundreds of studies reviewed by Steel, a psychologist states that to procrasinate is “to voluntarily delay an intended course of action despite expecting to be worse-off for the delay”. Another expert Dr. Joseph R. Ferrari, distinguishes between “chronic” or “real” procrastinators into three types: stimulation types avoiders and decisional procrastinators. Chronic procrastinators self-esteem.

Tice and Baumeister found that procrastinators get lower grades and have higher levels of stress. Chu and Choi, say that “Passive procrastinators” are more stressed and so less efficient. “Active procrastinators prefer to work under pressure” and “if something unexpectedly comes up, they will knowingly switch gears and engage in new tasks they perceive as more urgent.

Fair Draft

Procrastination

Procrastination is a Latin word. Hundreds of studies reviewed by Steel, a psychologist states that to procrastinate is “to voluntarily delay an intended course of action despite expecting to be worse-off for the delay”. Another expert, Dr. Joseph R. Ferrari, distinguishes between “chronic” or “real” procrastinators. Ferrari categorizes procrastinators into three types: stimulation types avoiders and decisional procrastinators. Chronic procrastinators have low self-esteem.

Tice and Baumeister found that procrastinators get lower grades and are stressed. Chu and Choi, say that “Passive procrastinators” are more stressed and less efficient. “Active procrastinators” work under pressure and if something more urgent comes up they change their focus.

No. of words in the summary: 104

Note-making
Title: Procrastination

1. Intro A proctn
Origin – Latin
Meaning – Put fwd till tomorrow – Idea A postponement or delay Steel (psychologist) – voluntary delay – despite expecting to be worse-off

2. Categorn
a. Dr. Joseph R. Ferrari
Stimln types – thrill 4m beating a deadline
Avoiders – avoid things // make others think badly A them
Decisional – postpone making a decsn (until enough information)
Real procs – way A life (might need therapy)
Chronic procs:
Low self esteem
Focus on past

b. Tice and Baumeister
Procs got lower grades
Higher levels A stress and illness

c. Chu and Choi
Passive procs – stressed, less efficient
Active procs – prefer to work under pressure, knowingly engage in new tasks

Conclusion: The word procrastination comes from two Latin terms meaning to ‘put forward until tomorrow’.
Abbreviations: Intro – Introduction; A – of; Proctn – procrastination; Fwd – forward; Stimln – stimulation; Categorn – categorization; 4m – from; // – that; decsn – decision; procs – procrastinators

44.

What is the largest positive integer such that \(\frac{n^2 + 7n + 12}{n^2 - n - 12}\) also a positive integer?1. 62. 163. 124. 8

Answer» Correct Answer - Option 3 : 12

Calculation:

\(\frac{n^2 + 7n + 12}{n^2 - n - 12}\)

⇒ \(\frac{{{n^2} + 3n + 4n + 12}}{{{n^2}\;- 4n + 3n + 12}}\)

⇒ \(\frac{{n\left( {n + 3} \right) + 4\left( {n + 3} \right)}}{{n\left( {n - 4} \right) + 3\left( {n - 4} \right)}}\)

⇒ \(\frac{{\left( {n + 3} \right)\left( {n + 4} \right)}}{{\left( {n - 4} \right)\left( {n + 3} \right)}}\)

⇒ \(\frac{{\left( {n + 4} \right)}}{{\left( {n - 4} \right)}}\)

⇒ \(\frac{{\left( {n - 4 + 4 + 4} \right)}}{{\left( {n - 4} \right)}}\)

⇒ \(1 + \;\frac{8}{{\left( {n - 4} \right)}}\)

Which will be maximum when (n - 4 = 8)

So, n = 12

∴ The largest positive integer is 12.

45.

Tomorrow summary

Answer»

In the story Tomorrow by Joseph Conrad, Captain Hagberd plans what he will do when his son, Harry who has been away at the sea for 16 years comes back. He hopes to marry him to the sweet girl who lives in the neighbourhood. After his wife passes away he redoubles his efforts to find his son. He tells himself every day that his son will return tomorrow.

He lives in the little seaport of Colebrook and hopes that his son will return to the place where he stayed once. He builds two small cottages. He prepares one for his son's return and lets out the other to his tenants, an old blind man and his daughter Bessie. Initially the local people make fun of him but they accept his ways and his unusual attire in the course of time. They pity him.

When the young man comes home unexpectedly many secrets about the characters in the story are revealed.

The story tells about the lives of three characters, the father Captain Hagberd, the wild son who returns home from America and the girl who stays next door, who dreams of being released from her hellish existence.

46.

What kind of life had harry lived after he left home

Answer»

His life was quite happening as he told Bessel that I’ve been everything you can think of almost but a tailor or soldier. I’ve been a boundary rider; I’ve sheared sheep, and humped my swag, and harpooned a whale. I’ve rigged ships, and prospected for gold, and skinned dead bullocks, —and turned my back on more money than the old man would have scraped in his whole life.

47.

वह छोटी-सी-छोटी संख्या ज्ञात करो जिससे 180 को गुणा करने पर वह इस प्रकार प्राप्त परिपूर्ण वर्ग का वर्गमूल भी ज्ञात करो ।

Answer»

5

यह स्पष्ट है कि पूर्ण वर्ग के लिए एक 5 और चाहिए। 

अत:दी गई संख्या को 5 से गुणा करने पर प्राप्त गुणनफल पूर्ण वर्ग संख्या होगी। 

∴ 180 x 5 = 900 एक पूर्ण वर्ग संख्या है।

48.

I. ` 56x^(2) + 37x + 6 = 0` II. ` 66y^(2) - 13y - 4 = 0`A. `x gt y`B. ` x lt y`C. ` x ge y`D. ` x le y`

Answer» Correct Answer - C
49.

Lohit, as an airman, is twice as capable as Aayush and together they finish a job in 17 days. In how many days does Aayush alone finish the same work?A. 34B. 51C. 68D. 401. D2. B3. A4. C

Answer» Correct Answer - Option 2 : B

Given:

Aayush and Lohit together can finish in 17 days.

Lohit efficiency = 2 × Aayush efficiency

Calculation:

Lohit efficiency = 2

Aayush efficiency = 1

Lohit + Aayush Efficiency

⇒ 2 + 1 = 3

Aayush and Lohit together can finish in 17 days

Total work

⇒ 17 × 3

⇒ 51

Aayush can finish alone 

⇒ 51/1

⇒ 51 days

∴ Aayush can finish alone in 51 days.

50.

Taking force length and time to be the fundamental quantities find the value of pressure

Answer»

As we know that, 
The dimension of Force is MLT-2
We have to derive dimension of Pressure
Also Pressure = Force / Area  
The dimension of Area = L2
The dimension of Force now = F
so,  P = FL-2