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Let \alpha and \beta   be the roots of equation

x^{2}-6x-2=0.\; if a_{n}=\alpha ^{n}-\beta ^{n},\; for\: n\geq 1,\; then\; the \: value\; of\; \frac{a_{10}-2a_{8}}{2a_{9}}

is equal to:

  • Option 1)

    6

  • Option 2)

    -6

  • Option 3)

    3

  • Option 4)

    -3

Option 1) 6 Option 2) -6 Option 3) 3 Option 4) -3
  Kirchoff's first law - - wherein   Apply Kcl at Q I6+I3 = I1+ I2   .........(1) I1 = 0.3A I4 = 0.8A I5 = 0.4A KCL at 5 I4= I5 +I3 I3 = I4 - I5     = 0.8 +0.4     =0.4A KCL at R I1+I2 = I4 I2 = I4 - I1     = 0.8 - (-0.3)     =1.1A From equation (1) I6 + I3 = I1+ I2 I6 = I1 + I2 - I3     = -0.3+1.1 -0.4     =0.4A I2 = 1.1A I3 = 0.4A I6 = 0.4A

Identify which set of figures follows the rule

SORRY A CORECTIONIN MY ANS - CIRCLE GETS CLOSED , BY MISTAKE I TYPED OPENED

  1. 121

  2. 61

  3. 74

  4. 101

This is  the figure.   The correct answer should be 121. As the logic here is , the outer circle figures should be added and their perfect square should be there in the inner circle. I.e. (2+6=8) and the 8^2=64. Hence, (8+3=11) and its perfect square is 121.
  1. Sri Lanka

  2. Bangladesh

  3. Pakistan

  4. Singapore

The correct answer option is 4 i.e. Singapore as except Singapore , rest 3 countries lie on India’s sub continent.

A.The reasons why piracy flourishes are two.

B. The problem is not with the laws but with enforcement.

C. Somehow they still do not realize the seriousness of the crime or its economic ramifications.

D. I have been a part of a drive against copyright theft for over two decades now.

E. The first is the lack of awareness amongst the enforcement agencies.

  1. ADBCE

  2. AECBD

  3. DBAEC

  4. ABDEC

The correct option will be option 3. After reading the sentences, it should be clear that AE should definitely come after each other because they form a pair. There are two options which suffice this i.e. 2 and 3. Now, starting with D helps to locate the topic on which these lines have been written i.e. copyright theft and A states the reason.
  1.  -5
  2. 6
  3. 1
  4. -3
Volume of parallelopiped,  Here  and,  Given that V is 546, put it in the above equation. Option (4) is correct

1) fast driving

2) drinking and driving

3) not following traffic regulations

4) giving signals

Option (4) is correct Because rest options are the reason for car accidents.

\int_{0}^{\pi /2} \frac{1}{1+\sqrt{tanx}} dx

  1. \pi

  2. \pi/2

  3. \pi/4

  4. 3\pi/2

...............................(1) We also know that,  Using this property in equation (1) ,  .....................(2) Adding equation (1) and (2),  Option (3) is correct
  1. x2+y2-3x+1=0
  2. x2+y2-x+5=0

  3. x2+y2-8x+6y=8

  4. x2+y2-4x+8y=7

General equation of circle ,  Now find the points of intersection of the two circles. At the intersection,              Putting the value of x1 in the equation of any of the two circle to find y1. Now we have 3 points through which the circle is passing,     ,       ,     Now putting these points in general equation we will have 3...
  1. \frac{x}{\sqrt{1+x^{2}}}
  2. \frac{1}{\sqrt{1+x^{2}}}
  3. \frac{\sqrt{1+x^{2}}}{x}
  4. \sqrt{1+x^{2}}
Let  Using Pythagoras theorem,  Option (2) is correct

artificial chemical means. The most common agent used today is formaldehyde, which is infused to replace body fluids.

The second sentence can best be replaced by:

1) Body fluids are replaced by formaldehyde, the most widely used agent today.

2) The most common agent "body fluids" are used to replace formaldehyde.

3) Formaldehyde is most widely used today along with the body fluids.

4) To replace body fluids the most common agent is to be used.

The correct answer is option 1 as it covers the necessary details clearly. In option 2, most common agent is mentioned as ‘body fluids’ which is wrong. In option 3, it is written that formaldehyde is used with body fluids which is wrong as it replaces body fluids. In option 4, formaldehyde is not mentioned.

(1+\omega^{2}-\omega)(1-\omega^{2}+\omega) is

  1. 4

  2. \omega

  3. 2

  4. Zero

With the help of 2 properties of cube roots of unity, we can solve this question. Property 1,  Property 2,  Now we have to find the value of (1+-)(1-+) Using property 2,  Now use property 1, Option (1) is correct  
  1. A thioether

  2. A secondary alcohol

  3. A primary alcohol

  4. A ether

A haloalkane on treatment with NaOR forms ether. Option (4) is correct

 

  1. 1^{0} amine with same number of carbons

  2. 1^{0} amine with one carbon less

  3. 2^{0} amine with one carbon less

  4. 1^{0} amine with one carbon more

option 2

 

  1. Two 2-centre 3-electron bonds and four 3-centre 2 -electron bonds
  2. Four 2-centre 3-electron bonds and two 3-centre 2 -electron bonds

  3. Four 2-centre 2-electron bonds and two 3-centre 2 -electron bonds

  4. Two 2-centre 2-electron bonds and four 3-centre 2 -electron bonds

Four 2-centre 2-electron bonds -   4 B-H Two 3-centre 2 -electron bonds  - 2 B-H-B (one Electron of B and on electron H) Option (3) is correct Diborane structure involves Four 2-centre 2-electron bonds and two 3-centre 2 -electron bonds
  1. Na

  2. Mg

  3. Al

  4. K

E.C. of all the elements. 1) Na = Ne 3s1 2) Mg = Ne 3s2 3) K = [Ar] 4s1 4) Al  = [Ne] 3s2 3p1   Now to compare second ionization energy the conf. will be   1) Na = Ne 2) Mg = Ne 3s1 3) K = [Ar] 4) Al  = [Ne] 3s2   Now Sodium and Potassium have achieved their stable conf. i.e noble gas conf. or now are fully filled and thus more stable than Mg and Al. Now in K and Na, Na will have highest second...
  1. 8

  2. 6

  3. 4

  4. 2

This is a charge balancing question.  Fe exists in two forms mainly Ferrous (Fe2+) and Ferric (Fe3+). Let there are 100 oxygen atoms and x number of Fe3+ atoms and 96-x number of Fe2+ atoms. Balance charge The percentage of  Fe3+ ions is,     Option (1) is correct.
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