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.

A promissory note does not require ……

Answer»

A promissory note does not require Acceptance.

2.

Who are the parties to a bill of exchange ?

Answer»

There are three parties to a bill of exchange:

1. Drawer – He is the creditor who draws a bill of exchange upon the debtor.

2. Drawee – He is the person upon whom the bill of exchange is drawn. He is the purchaser of the goods on credit and the debtor.

3. Payee – He is the person to whom payment of the bill is to be made on the maturity date. The drawer and the payee can be one party when payment is to be made to the drawer.

3.

Locate the centroid of the T-section shown in the Fig.

Answer»

Selecting the axis as shown in Fig. we can say due to symmetry centroid lies on y axis, i.e. x = 0. 

Now the given T-section may be divided into two rectangles 

A1 and A2 each of size 100 × 20 and 20 × 100. The centroid of A1 and A2 are g1(0, 10) and g2(0, 70) respectively. 

∴ The distance of centroid from top is given by:

\(\bar y\) = \(\frac{100\times20\times10+20\times100\times70}{100\times20+20\times100}\)

= 40 mm

Hence, centroid of T-section is on the symmetric axis at a distance 40 mm from the top.

4.

Determine the centroid of the wire shown in Fig. 

Answer»

The wire is divided into three segments AB, BC and CD. 

Taking A as origin the coordinates of the centroids of AB, BC and CD are 

G1(300, 0); G2(600, 100) and G3 (600 – 150 cos 45°, 200 + 150 sin 45°) 

i.e., G3 (493.93, 306.07) 

L1 = 600 mm, L2 = 200 mm, L3 = 300 mm 

∴ Total length L = 600 + 200 + 300 = 1100 mm 

∴ From the eqn. Lxc = ΣLi xi , we get 

1100 xc = L1x1 + L2x2 + L3x3 

= 600 × 300 + 200 × 600 + 300 × 493.93 

∴ xc = 407.44 mm 

Lyc = ΣLi yi 

1100 yc = 600 × 0 + 200 × 100 + 300 × 306.07 

∴ yc = 101.66 mm

5.

A solid block of mass `m = 1 kg` is reasting on a horizontal platform as shown in figure. The `z` direction is vertically up. Coefficient of friction between the block and the paltform is `mu = 0.2`. The platform is moved with a time dependent velocity given `vec(V) = (2that(i) + that(j) + 3hatk) m//s`. Then the magnitude of the net force exerted by the block on the platform is : (Take `g = 10 m//s^(2)`) A. `sqrt(168)N`B. `sqrt(174)N`C. `sqrt(194)N`D. None of these

Answer» Correct Answer - B
Acceleration of the platform
`overset(vec)(a_(p) ) - (doverset(vec)v)/(dt) - 2hati + hat(j) + 3hat(k)`
Horizontal force on the block
Normal force on the block
`a_(H) = sqrt(4 + 1) = sqrt(5) m//s^(2)`
`a_(v)= 3 m//s^(2)`
Normal force on the block
`N = m (g + a_(v)) = 1 xx 13 = 13N`
Maximum acceleration that friction can positive
`a_(mass) = mu(g + a_(y)) = 0.2 xx 13 = 206 m//s^(2)`
`:. a_(max) gt a_(H)`
`:.` Value of frication force on the block
`f = ma_(H) = sqrt(5)N`
`:.` Force by the platform on the block is
`F = sqrt(N^(2) t^(2)) = sqrt(169 + 5) = sqrt(174)N`
6.

A cylinder of mass M and radius r is suspended at the corner of a room. Length of the thread is twice the radius of the cylinder. Find the tension in the thread and normal force applied by each wall on the cylinder assuming the walls to be smooth. A. `T = sqrt(3)Mg, N = (Mg)/(sqrt(3))`B. `T = sqrt(2)Mg, N - (Mg)/(sqrt(2))`C. `T = (sqrt(3)Mg)/(2), N = (Mg)/(sqrt(3))`D. `T = sqrt(3)Mg, N = (2Mg)/(sqrt(3))`

Answer» Correct Answer - B
7.

The cofactor of - 4 in the matrix \( \begin{bmatrix}-4 & -3 & -3 \\[0.3em]1 & 0 & 1 \\[0.3em]4 & 4 &3\end{bmatrix}\) is(A) - 4(B) - 3(C) - 2(D) 4

Answer»

Correct option is: (A) - 4

8.

If Cij denotes the cofactor of element pij of the matrix P = \(\begin{bmatrix}1 & -1 & 2 \\[0.3em]0 & 2 & -3 \\[0.3em]3 & 2 & 4\end{bmatrix}\)then the value of C31 . C23 is :[(1,-1,2),(0,2,-3),(3,2,4)](a) 5(b) 24(c) - 24(d) - 5

Answer»

Option : (a) 5

Option: (a) 5

Cij=(-1)I+j

C31=(-1)*(-3)-2*2=3-4=-1

C23=2*1-(-1)*3=2+3=5

C31=(-1)3+1*(-1)=-1

C23=(-1)3+1*5=5

(-5)*(-1​​​​)=5

Option:(a)

9.

Compare isothermal and an adiabatic process.

Answer»
Isothermal changeAdiabatic change
1. Changes in volume and pressure of a gas taking place at constant temperature are called isothermal changes.1.Changes in volume and pressure of a gas taking place in a thermally isolated system are called adiabatic changes.
2. Temperature of the gas remains constant.2. Temperature of the gas changes.
3. The gas remains in good thermal contact with the surroundings and heat is exchanged.3. The gas is isolated from the surroundings and heat is not exchanges ∆Q = O.
4. Internal emergy remains constant. Change in internal energy ∆ U = O.4. Internal energy changes. 
5. This process takes place slow. 5. This process takes place quickly
6. Boyle's law PV = Constant holds good6. PVr = Constant
7. Workdone W = RT loge(v2/v1)7. Work done w = (R/(r - 1))(T1 - T2)
10.

Consider the following statements:(1) The ideal of what the child should become(2) The common beliefs of society's members, even though individuals or groups of them may have different beliefs1. (1) is the cause and (2) is the effect2. (1) is the effect and (2) is the cause3. (1) and (2) are unrelated4. (1) and (2) are related but there is no cause effect relationship

Answer» Correct Answer - Option 3 : (1) and (2) are unrelated

(1) The ideal of what the child should become

(2) The common beliefs of society's members, even though individuals or groups of them may have different beliefs

(1) and (2) are unrelated

11.

between the masses and with the wall are perfectly elastic , the possible no. of collisions between the bodies and the wall together is[a] 1[b] 2[c] 3[d] infinity

Answer»

First the ball ahead of the other will collide with the wall and reverse its direction and move with same speed.

After that it would collide with the ball approaching it with same speed and exchange the velocities. Hence the rear ball will move backwards with same speed but the ball which was ahead would again move towards wall with same speed.

The ball will again collide with wall and reverse its direction and move with same speed again(behind the other ball) forever.

Hence the total number of collisions is 3.

12.

Consider the following notions of Erick Erickson:(1) struggle to find a balance between developing a unique, individual identity while still being accepted and fitting in(2) intensive analysis and exploration of different ways of looking at oneself.1. (1) is related to identity vs. role crisis (2) is related to Industry (competence) vs. Inferiority2. (1) is related to Intimacy vs. Isolation and (2) is related to identity vs. role crisis3. (1) and (2) are related to Industry (competence) vs. Inferiority4. (1) and (2) are related to identity vs. role crisis

Answer» Correct Answer - Option 4 : (1) and (2) are related to identity vs. role crisis

Erik Erickson' notions of child pedagogy:

  • According to Erik Erikson, a prominent developmental theorist of the 1950's, youth must resolve two life "crises" during adolescence. Unlike many other developmental theorists of his era, Erikson's psychosocial theory of human development covers the entire lifespan, including adulthood.
  • Erikson used the term "crisis" to describe a series of internal conflicts that are linked to developmental stages. 
  • The first crisis typically occurs during early to middle adolescence, and is called the crisis of identity versus identity confusion. This crisis represents the struggle to find a balance between developing a unique, individual identity while still being accepted and "fitting in." Thus, youth must determine who they want to be, and how they want to be perceived by others.
  • Erikson believed that when youth successfully navigate this crisis they emerge with a clear understanding of their individual identity and can easily share this "self" with others; therefore, they are healthy and well-adjusted. According to Erikson, an identity crisis is a time of intensive analysis and exploration of different ways of looking at oneself.

Both the statements are related to identity vs role crisis notions of Erik Erickson.

Hence, the correct answer is Option 4.

13.

Explain conduction, convection and radiation with examples.

Answer»

The heat is transmitted in three types. They are

(1) Conduction

(2) Convection

(3) Radiation.

(1) Conduction : The process of transmission of heat from one place to other without actual movement of the particles of the medium is called conduction.

Ex : When long iron rod is heated at one end, heat transmits to the other end.

(2) Convection : The process of transmission of heat from one place to another by the actual movement of the particles is called convection. 

Ex. : If water in a beaker is heated, the particles of water at the bottom receive the heat first. These particles expand, become lighter and rise up. At the same time colder and denser particles reach the bottom. They get in their turn heated and move up. This process is known as convection.

(3) Radiation : The process of transmission of heat from one place to another without any intervening medium is called radiation.

Ex. : Earth receives heat radiations from the sun.

14.

The formation of image in a convex lens when the object is between F and 2F

Answer»

When an object is placed between F and 2F in front of a convex lens, the image formed is magnified, real, inverted and beyond 2F.

15.

Acceleration of train when it is moving steadily from 4.0 m s-1 to 20 m s-1 in 100 s is A. 1 m s-2 B. 2 m s-2 C. 0.16 m s-2 D. 3 m s-2

Answer»

C. 0.16 m s-2

16.

If we get a straight line with positive slope then its acceleration is A. increasing B. decreasing C. zero D. constant

Answer»

D. constant.

17.

A train travelling at 20 m s-1 accelerates at 0.5 m s-2 for 30 s, the distance travelled by train is A. 825 m B. 700 m C. 650 m D. 600 m

Answer»

 The Correct option is A. 825 m

18.

Horizontal distance travelled by a ball if it's thrown with initial velocity of 20 m s-1 at an angle of 30° is A. 24 m B. 56 m C. 35.3 m D. 36.3 m

Answer»

The Correct option is C. 35.3 m

19.

If a spinster staring from rest has acceleration of 5 m s-2 during 1st 2.0 s of race then her velocity after 2 s is A. 20 m s-1 B. 10 m s-1 C. 15 m s-1 D. 5 m s-1

Answer»

The Correct option is B. 10 m s-1

20.

If a car starting from rest reaches a velocity of 18 m s-1 after 6.0 s then its acceleration is A. 1 m s-2 B. 2 m s-2 C. 3 m s-2 D. 4 m s-2

Answer»

The Correct option is C. 3 m s-2

21.

As the ball falls towards the ground, its velocity A. increases B. decreases C. remains constant D. becomes zero

Answer»

A. increases

22.

An object whose velocity is changing is said to be in a state of A. acceleration B. rest C. equilibrium D. Brownian motion

Answer»

A. acceleration

23.

Acceleration of free fall depends on the A. surface B. weight of object C. distance from center of Earth D. size of object

Answer»

B. weight of object 

24.

Gradient of velocity-time graph tells us about object's A. velocity B. displacement C. distance D. acceleration

Answer»

D. acceleration

25.

A stone is thrown upwards with initial velocity of 20 m/s, the height that stone will reach would be A. 20 m B. 30 m C. 40 m D. 50 m 

Answer»

The Correct option is A. 20 m

26.

List out the laws of photoelectric effect

Answer»

Laws of photoelectric effect:

  • For a given frequency of incident light, the number of photoelectrons emitted is directly proportional to the intensity of the incident light. The saturation current is also directly proportional to the intensity of incident light. 
  • Maximum kinetic energy of the photo electrons is independent of intensity of the incident light. 
  • Maximum kinetic energy of the photo electrons from a given metal is directly proportional to the frequency of incident light. 
  • For a given surface, the emission of photoelectrons takes place only if the frequency of incident light is greater than a certain minimum frequency called the threshold frequency.
  • There is no time lag between incidence of light and ejection of photoelectrons.
27.

Find the mean deviation about the mean for the following data.Marks obtained10-20   20-30    30-40    40-50    50-60   60-70   70-80   Number of students23814832

Answer»
Marks obtainedNumber of students fiMidpoints Xifi xi |xi - x|fi|xi - x|
10-20212303060
20-30325752060
30-408352801080
40-50144533000
50-608554401080
60-703651952060
70-802751503060
N = 40 = ∑f1800∑f|x1 - x|2 = 400


Bar x = (∑fixi)/N = 1800/40 = 45

MD (x) = 10.

28.

If \( 2 \cos \theta=\sqrt{x}+\frac{1}{\sqrt{x}} \) for some \( x>0 \), then which one of the following is not equal to \( \cos (5 \theta) \) (a) \( \frac{1}{2}\left(x^{5 / 2}+\frac{1}{x^{5 / 2}}\right) \) (b) \( \frac{1}{2}\left(x^{3 / 2}+\frac{1}{x^{3 / 2}}\right) \) (c) 1 (d) \( -1 \)

Answer»

Correct option is (a) \(\frac12(x^{5/2}+\frac1{x^{5/2}})\)

2 cos θ = \(\sqrt x+\frac1{\sqrt x}\)-----(1)

4 cos2 θ = x + 1/x + 2----(2) (By squaring (2))

and 8 cos3θ = x3/2 + \(\frac1{x^{3/2}}\) + 3\(\sqrt x\) x \(\frac1{\sqrt x}\) (\(\sqrt x+\frac1{\sqrt x}\)

 = x3/2 + \(\frac1{x^{3/2}}\) + 3 (\(\sqrt x+\frac1{\sqrt x}\))---(3)

Now, cos 5θ = cos(4θ  + θ)

 = cos 4θ.cosθ - sin 4θ sin θ

 = (2cos2θ -1) cos θ - 2 sin 2θ cos2θ sin θ

 = (2(2cos2θ  - 1)2 - 1) cos θ - 4 sin2θ cos θ(2cos2 θ -1)

 = (2(4cos4θ  - 4 cos2θ +1)-1) cos θ - 4(1- cos2θ)(2cos3θ - cos θ)

 = (8 cos4θ  - 8 cos2θ  + 2 - 1) cos θ - 4(-2cos5θ + 2cos3θ  + cos3θ - cos θ)

 = 8 cos5θ - 8 cos3θ + cos θ + 8cos5θ - 12 cos3θ + 4cos θ

 = 16 cos5θ - 20 cos3θ + 5 cos θ

 = \(\frac12(8 cos^3\theta\times4cos^2\theta)-\frac52(8cos^3\theta)\) + \(\frac52\)(2cos θ)

 = \(\frac12((x^{3/2}+\frac1{x^{3/2}}+3(\sqrt x+\frac1{\sqrt x}))\)\((x+\frac 1x+2)\))

 = \(\frac12\Big(x^{3/2}+\frac1{x^{1/2}}+3x^{3/2}+3x^{1/2}+\frac1{x^{5/2}}+\frac3{x^{1/2}}+\frac3{x^{3/2}}\)

\(+2x^{3/2}+\frac2{x^{3/2}}+6x^{1/2}+\frac6{x^{1/2}}-5x^{3/2}-\frac5{x^{3/2}}\)

\(-15x^{1/2}-\frac{15}{x^{1/2}}\Big)\) 

 = \(\frac12(x^{5/2}+\frac1{x^{5/2}}+x^{3/2}(3+2-5)+\frac1{x^{3/2}}(3+2-5)\)

\(+x^{1/2}(3+1+6-15+5)+\frac1{x^{1/2}}(1+3+6-15+5))\)

\(\frac12(x^{5/2}+\frac1{x^{3/2}}+x^{3/2}(5-5)+x^{1/2}(15-15)+\frac1{x^{1/2}}(15-15))\)

\(\frac12(x^{5/2}+\frac1{x^{5/2}})\)

29.

(ii) \( \sin ^{-1} \frac{3}{5}+\cos ^{-1} \frac{12}{13}=\cos ^{-1} \frac{33}{65} \)

Answer»

sin-1\(\frac35\) + cos-1\(\frac{12}{13}\)

 = tan-1\(\frac34\) + tan-1\(\frac5{12}\) 

 = tan-1\(\left(\cfrac{\frac34+\frac5{12}}{1-\frac34\times\frac5{12}}\right)\)

 = tan-1\((\frac{56}{33})\)

 = cos-1\((\frac{33}{\sqrt{56^2+33^2}})\) = cos-1\((\frac{33}{65})\)

Hence Proved

30.

13. \( \cos ^{2} \theta+\frac{1}{1+\cot ^{2} \theta}=1 \)

Answer»

cos2x+1/cosec2x=1

cos2x +sin2x=1

Hence proved.

31.

\(\displaystyle\int_{a+c}^{b+c}f(x)dx = \ ?\)1. \(\displaystyle\int_a^b f(x-c)dx\)2. \(\displaystyle\int_a^b f(x+c)dx\)3. \(\displaystyle\int_a^b f(x)dx\)4. \(\displaystyle\int_{a-c}^{b-c} f(x)dx\)

Answer» Correct Answer - Option 2 : \(\displaystyle\int_a^b f(x+c)dx\)

Explanation:

Given Integral is,

\(I~=~\displaystyle\int_{a+c}^{b+c}\ f(x)dx\)

Put t = x - c i.e. x = t + c

By differentiating we have,

dt = dx

at x = a + c  →  t = a + c - c = a ........(1)

at x = b + c  →  t = b + c -c = b .........(2) 

Now,

\(\displaystyle\int_{a+c}^{b+c}f(x)dx =~\int_a^b f(t+c)dt \)  .........(3)

Also, put t = x then,

t = a →  x = a ,,,,,,from equation (1)

t = b →  x = b ......from equation (2)

From the equation (3)

\(\displaystyle\int_{a+c}^{b+c}f(x)dx =~\int_a^b f(x+c)dt \)

Hence, it is proove.

32.

Area bounded by the curve xy = c and the x-axis between x = 1 and x = 4, is:1. c(log 3) sq. units2. 2c(log 3) sq. units3. 2c(log 2) sq. units4. 2c(log 5) sq. units

Answer» Correct Answer - Option 3 : 2c(log 2) sq. units

Concept:

  • The area under the function y = f(x) from x = a to x = b and the x-axis is given by the definite integral \(\rm \left| \int_{a}^{b}f(x)\ dx \right|\), for curves which are entirely on the same side of the x-axis in the given range.
  • Definite integral: If ∫ f(x) dx = g(x) + C, then \(\rm \int_{a}^{b}f(x)\ dx=[g(x)]_{a}^{b}\) = g(b) - g(a).
  •  \(\rm \int{\frac{1}{x}dx}\) = log x + C.

 

Calculation:

The given equation is of the curve is xy = c, which can also be written as y = f(x) = \(\rm \frac{c}{x}\).

Using definite integrals, the area under the curve from x = 1 to x = 4 and the x-axis, will be given as:

A = \(\rm \left| \int_{1}^{4}{\frac{c}{x}}\ dx \right|\)

Using \(\rm \int{\frac{1}{x}dx}\) = log x + C, we get:

⇒ A = \(\rm c\left[ \log x \right]_{1}^{4}\)

⇒ A = c(log 4 - log 1)

Using log 1 = 0 and log 4 = 2 log 2, we get:

⇒ A = 2c(log 2) sq. units

33.

If \(\displaystyle\int_0^1 \dfrac{e^t}{1+t}dt=a\), then \(\displaystyle\int_0^1 \dfrac{e^t}{(1+t)^2}dt=\)1. \(a-1+\dfrac{e}{2}\)2. \(a+1+\dfrac{e}{2}\)3. \(a-1-\dfrac{e}{2}\)4. \(a+1-\dfrac{e}{2}\)

Answer» Correct Answer - Option 4 : \(a+1-\dfrac{e}{2}\)

Explanation:

Given Integral is,

\(\displaystyle∫_0^1 \dfrac{e^t}{1+t}dt=a\)

Considering \(I_1 ~=~\frac{1}{1+t}\) and \(I_2 ~=~e^t \)

Hence by Integration by parts we know that,

∫ [I1][ I2 ] dt = I1∫ I2 dt - ∫ [I'1∫ I2 dt]dt

\(\frac{1}{1+t}\int_0^1 e^t dt-\int_0 ^1 [\frac{d}{dt}(\frac{1}{1+t}).\int_0 ^1 e^t dt]dt~=~a\)

\(\frac{1}{1+t}[e^t ]_0^1-\int_0^1 (\frac{-1}{(1+t)^2}).e^t dt~=~a\)

\([\frac{e^t}{1+t}]_0^1 +\int_0^1 \frac{e^t}{(1+t)^2}dt~=~a\)

\(\int_0^1 \frac{e^t}{(1+t)^2}dt~=~a-[\frac{e^t}{1+t}]_0^1\)

\(\int_0^1 \frac{e^t}{(1+t)^2}dt~=~a-[\frac{e^1}{1+1}-\frac{e^0}{1+0}]\)

\(\int_0^1 \frac{e^t}{(1+t)^2}dt~=~a-[\frac{e}{2}-1]\)

\(\displaystyle\int_0^1 \dfrac{e^t}{(1+t)^2}dt~=~a+1-\frac{e}{2}\)

34.

The area of the region bounded by the curve y = f(x), x axis and the lines x = a and y = b, (b > a) is given by1. \(\displaystyle\int_a^b x \ dx\)2. \(\displaystyle\int_a^b y \ dy\)3. \(\displaystyle\int_a^b y \ dx\)4. \(\displaystyle\int_a^b x \ dy\)

Answer» Correct Answer - Option 3 : \(\displaystyle\int_a^b y \ dx\)

Explanation:

Area enclosed by a curve y = f (x) and x axis is given by:

A = ∫ f (x) dx

Since curve is bounded by lines x = a and y = b

i.e Lower limit for x = a and upper limit for  x = b (∵ b > a)

∴ \(A=\displaystyle\int_a^b f(x) \ dx\)

Since f(x) = y

Hence \(A=\displaystyle\int_a^b y \ dx\)

35.

Determine f(x) for f'(x) = \(\rm 4x^3 - 2 {1\over \sqrt x} + e^{-4x}\), and f(0) = \(3\over4\)1. x4 - 4\(\rm\sqrt x - {e^{-4x}\over4}\) + 12. x4 - 4\(\rm\sqrt x + {e^{-4x}\over4}\) + 13. x4 - \(\rm\sqrt x - {e^{-4x}\over4}\) + 14. x4 - 4\(\rm\sqrt x +e^{-4x}\) + 1

Answer» Correct Answer - Option 1 : x4 - 4\(\rm\sqrt x - {e^{-4x}\over4}\) + 1

Concept:

Integral property:

 
  • ∫ xn dx = \(\rm x^{n+1}\over n+1\)+ C ; n ≠ -1
  • \(\rm∫ {1\over x} dx = \ln x\) + C
  • ∫ eax dx = \(\rm e^{ax}\over a\)+ C
  • ∫ adx = (ax/ln a) + C ; a > 0,  a ≠ 1
  • ∫ sin x dx = - cos x + C
  • ∫ cos x dx = sin x + C
 

Calculation:

Given f'(x) = \(\rm 4x^3 - 2 {1\over \sqrt x} + e^{-4x}\)

f(x) = ∫ f'(x) dx

⇒ f(x) = \(\rm \int 4x^3 - 2 {1\over \sqrt x} + e^{-4x}\) dx

⇒ f(x) = \(\rm 4\left[{x^4\over4}\right] - 2\left[{x^{1\over2}\over{1\over2}}\right] + \left[{e^{-4x}\over-4}\right] \)

⇒ f(x) = x4 - 4\(\rm\sqrt x - {e^{-4x}\over4}\) + C

Now f(0) = \(3\over4\)

⇒  04 - 4\(\rm\sqrt 0 - {e^{-4(0)}\over4}\) + C = \(3\over4\)

⇒ C - \(1\over4\) = \(3\over4\)

⇒ C = 1

⇒ f(x) = x4 - 4\(\boldsymbol{\rm\sqrt x - {e^{-4x}\over4}}\) + 1

36.

(a)Acute angled (b)Obtuse angled (c) Right angled (d) Triangle can not be possibleTHESE OPTIONS ARE GIVEN IN MY BOOK

Answer»

Option is (b) obtuse angled triangle.

Explanation

Given ratio of the sides =2:6:7

Let the sides are 2x,6x and 7x unit.

Square of the longest side =49x2

Sum of the square of other two sides are = 4x2+36x2=40x2

If this is 49x2 then by Pythagoras theorem the triangle would be right triangle.

But  the sum is less than 49x2. So the triangle is obtuse one.

Mnemonic

If a,b,c are three sides of a triangle such that c is the longest side then

When c2 = a2+b2 -> triangle is rt angled

When c2 > a2 +b2 -> triangle is obtuse angled

When c2 < a2+b2-> triangle is acute angled

37.

(a)Acute angled (b)Obtuse angled (c) Right angled (d) Triangle can not be possibleTHESE OPTIONS ARE GIVEN IN MY BOOK

Answer»

Hence the correct answer is (b)Obtuse angled triangle.

38.

For example -- right angled triangle

Answer» Scalene triangle.is the answer. It has got three sides of unequal length.
39.

3sin inverse=sin inverse(3x-4x cube)

Answer» I think the question is

To prove     3arcsinx = arcsin(3x-4x^3)

Let x= sin A , then A = arcsinx so  LHS = 3A

and RHS = arcsin (3sinA-4sin^3A) = arcsin(sin3A)=3A

So LHS = RHS
40.

How much will the area increase if each side of rectangle is increased by 20%?My friend Vipul and I asked this Question but we didn't understand? So please solve this question in detail.

Answer»

Lets,

Original length = x m

Original breadth = y m

Original are = l x b

= x m x ym

= xy m2

Each side increased by 20%

Then,

length = 120x/100 = 6x/5 m

breadth = 120y/100 = 6y/5 m

Area = l x b

= 6x/5 x 6y/5 m2

= 36xy/25 m2

Different = 36xy/25 m2 - xy m2

= (36xy/25 - xy/1) m2

= (36xy - 25xy)/25 m2

= 11xy/25 m2

Increase% = (Different/ original) x 100%

= ((11xy/25 ) / xy)  x 100%

= (11xy/25) x (1/xy) x 100%

= 44%

41.

If \( x: y=5: 12 \) and \( z=52 cm \), find the perimeter of the triangle.

Answer»

13 = 52

1 = 52/13

= 4

5 + 12 + 13 = 30

Total perimeter = 30 x 4

= 120cm

42.

The length of the diagonals of a rhombus are 6 cm and 8 cm. Find the length of each side of the rhombus.

Answer»

We know diagonals bisects at right angle

∴ In △AOD

AO+ OD= AD2

(3)+ (4)= AD2

⇒ AD = 5 cm

The side of rhombus is 5cm.

43.

A mother devides Rs. 207 into three parts such that the amount are in A.P. and gives it to her three children. The product of the two least amounts that the children had Rs. 4623. Find the amount received by each child.

Answer» LET THREE PARTS ARE a-d,a,a+d
                              NOW ,a-d+a+a+d=207
                                                3a=207
                                                  a=69
AND ALSO,PRODUCT OF ANY TWO LEAST NUMBER IS 4623
              SO,         a(a-d)=4623
                             69(69-d)=4623
                                    d=2
         SO THREE PARTS ARE 67,69,71

a, a + d, a + 2d

a + a + d + a + 2d = 207

3a + 3d = 207

3(a + d) = 207

a + d = 207/3 = 69

a x (a + d) = 4623

a x 69 = 4623

a = 4623/69 = 67

a = 67

67 + d = 69

⇒ d = 69 - 67 = 2

a = Rs. 67

a + d = Rs. 69

a + 2d = Rs. 67 + (2 x 2) = Rs. 71

44.

Two APs have the same common difference. The first term of one AP is 2 and that of the other is 7. The difference between their 10th terms is the same as the difference between their 21st terms, which is the same as the difference between any two corresponding terms.

Answer»

Let a, d and an​ be the first term, common difference and nth term of first AP and

A, d and An​ be the first term, common difference and nth term of second AP respectively. 

 Given a=2 and A=7 

Also, given that, a10​−A10​=a + 9d − (A + 9d )= a − A = 2 − 7 = −5

and a21​ − A21 ​= a + 20d −(A + 20d) = a − A = 2 − 7 = −5

Hence, the difference between any two corresponding terms of these AP's is equal to difference between first terms of these AP's. 

∴   given statement is true so answer is 1.

45.

The figure below is a  __________ of urinal.(a) squatting type(b) bowl type(c) slab type(d) trough type

Answer» Right answer is (a) squatting type

To explain I would say: Urinals are basically of three types- Bowl type, Slab or stall type and squatting type.
46.

A metal parallel plate capacitor has ‘a’mm diameter and the distance between the plates is 1mm. The capacitor is placed in air. Force on each plate is 0.035N and the potential difference between the plates is 1kV. Find ‘a’.(a) 10mm(b) 100mm(c) 1000m(d) 1000cm

Answer» Right answer is (b) 100mm

To explain: From the given data:

A=pi*d^2/4=pi*a^2/4

Potential gradient = V/x = 10^6V/m

F=epsilon*A*(V/x)^2/2

Substituting the given values, we get d=100mm.
47.

Uncle captained India in test cricket and the nephew captained Pakistan. Can you name both?

Answer»

Ghulam Ahmed-India and Asif Iqbal-Pakistan

48.

The sum of the roots of the equation ax2+x+c=0 (where a and c are non-zero) is equal to the sun of the reciprocal of their squares. Then a, ca2, c2  are in (A) AP.  (B)GP (c) HP. (D)AGP

Answer»

SOLUTION
Let the roots of the equation be α and β.  Then  
       α +  β = 1/α²  +  1/β²

or,  α +  β = (α²+β²) / α²β²

or,  α +  β = ( α +  β)² - 2αβ   / α²β²

Putting the values of α +  β and αβ we get 

      -b/a =( (b²/a²) - 2c/a) / (c²/a²)

or,    -b/a = (b²- 2ac)/ c²

or,    -bc² = ab² - 2ca²

or    bc² + ab² = 2ca²

Hence bc² , ca², ab² are in A.P.

49.

This institution has Nasser Hussain as one of the honorary members. Formed in 1846, by the civil servant Alexander Arbuthnot on the “Island” Name the famous Indian club

Answer»

Madras Cricket Club

50.

In the metallic conductor the current is due to flow of chrge is ??

Answer»

In any metallic conductor the current is due to the flow of the charged particles. Current can flow due to ions or any other charge particle which are freely available for the movement through the conductor.