Conic Section MCQs

1. The line y=mx+c intersects the circle x²+y²=a² at the most of __________ points.
1. 1
2. 2
3. 3
4. 4


2. The line perpendicular to the tangent line is called ?
1. normal line
2. secant line
3. limit
4. derivative


3. The eccentricity of an ellipse is ?
1. e = 1
2. e < 1
3. e > 1
4. 0 < e < 1


4. The perpendicular distance from the point (3,-4) to the line
   3x²-4x+10=0
1. 7
2. 8
3. 9
4. 10


5. The point of a parabola which is closest to the focus is the __________ of the parabola.
1. vertex
2. latusrectum
3. directrix
4. eccentricity


6. The center of the circle 4x²+4y²-8x+12y-25=0 is ?
1. (2,-3)
2. (-2,3)
3. (-4,6)
4. (4,-6)


7. The radius of the circle 4x²+4y²-8x+12y-25=0 is ?
1. 
2. 
3. 
4. 


8. If the distance between vertex and focus is 3, then the length of latusrectum is ?
1. 6
2. 8
3. 10
4. 12


9. If the discriminent of a conic is h²-ab=0, then it represents a
1. circle
2. parabola
3. hyperbola
4. ellipse


10. The focus of the parabola y²=-8(x-3) is ?
1. (0,0)
2. (1,0)
3. (0,1)
4. (1,1)

Answer key

 

 

1. B
2. A
3. D
4. A
5. A
6. D
7. C
8. D
9. B
10. B

 

Physics Optics

A combination of two thin lenses in contact behave as converging lens of focal length 80 cm if one of the lense is convrging lens of focal length 20 cm,  the power of other lens will be

Explanation.
f= focul length of combination of two lenses
f1= focul length of ist lens
f2= focul length of 2nd lens
As 1/f =1/f1  + 1/f2
1/80 = 1/20 + 1/f2
1/f2 = 1/80 - 1/20
f2 = -26.66cm
 = -0.266 m

As Power of lens P= 1/f (where f will be in meters)

So
P=1/-0.266
= -3.75D

Some MCQs of Physics and Chemistry.

Q1)when the aircraft concorde is moving in horizontal plane at const speed 650 m/s its turning circle has radius of 80 km wat is ratio of centripetal force to the weight of air craft?
Ans.

Q2)when 0.24 gm of magnesium is reacted with excess HCl what volume of gas librated at RTP
Ans.

Q3)In mixture of NO and CO2 initialy containing 4 mol of NO and 0.9 mol of CO2 reaction ocur acording to NO+CO2>NO2+CO at eq 0.1 mol of CO2 was presnt what is Kc
Ans.

Q4)a box of mas m =6 kg slid with speed v=4 m/s acros frictionless flor it sudenly explodes into 2 pieces one piece with mass m1 =2kg moves in same direction with speed v1=8 m/s find velocity of 2nd piece
Ans. as momentum before collision= momentum after collision
for m2 ,m=m1+m2 6=2+m2 m2=4kg so 6(4)=2(8)+4(x) 8=4x x=2m/s

Q5)Q2) on groud the gravitational force on satelite is W wat is gravitational force on satelite when at height R/50 where R is radius of earth
Ans. On the ground, the distance (from the centre of the Earth) is R. In orbit, the distance is R+R/50 or (51/50)R. The force is (ETA: inversely) proportional to the square of the distance so the multiplier you want is (50/51)^2 ~=0.96W

Q6)equal weights of methane and hydrogen are mixed in an an empty container at 25 degre centegrad the fraction of total presure exerted by hydrogen is.
Ans. apply mole fraction formula by daltons law of partial pressure
as moles fraction=no of moles of components/no of total moles let no of moles H2= n/2 let no of moles of CH4=n/16 total moles = n/2 + n/16 =9n/16 so mole fraction of pressure exerted byH2= n/2 ÷ 9n/16 = n/2 × 16/9n =8/9 ans

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solve coding and decoding aptitude questions 2

Here Example No1
If MOBILE is coded as OQDKNG. How will you code TABLET.

Solution:

This question is similar to the previous one. Only the difference is that the alphabet is to two letters ahead.



M —–(N)——> O

O —–(P)——> Q

B —–(C)——> D

I —–(J)——> K

L —–(M)——> N

E —–(F)——> G



In the same way we have to code for TABLET



T —–(U)——> V

A —–(B)——> C

B —–(C)——> D

L —–(M)——> N

E —–(F)——> G

T —–(U)——> V



Thus TABLET should be coded as VCDNGV.

example 2
n certain code BRAIN is coded as CQBHO. How will you code TALENT?

Here the the question does not look simple. But when you write the letters in sequence it becomes simple one.

B —–>C

R<—– Q

A——>B

I<——H

N——>O

Here letters are shifted alternately one step forward and backward. Therefor in same code we can write code for talent as

T —–>U

A<—– Z

L——>M

E<——D

N——>O

T<——S

Thus we can code TALENT as UZMDOS

example no 3
If POOR is coded as ONNQ. How will you code RICH?

This question becomes simple to solve when you write the word and its code vertically in front of each other?

P <—–O

O<—– N

O<——N

R<——Q

We can easily decode the sequencing of alphabate in above code. Here each letter is shifted backward by one letter. Therefor in similar way we can write the code for RICH as follows

R <—–Q

I <—– H

C <——B

H<——G



Thus the code for RICH is QHBG.

ECAT MCQs Part 1

1. Converse of pair production is
   a)compton effect
   b)annihilation of matter
   c)photoelectric effect
   d)none of them
2. de broglies hypothesis was experimentally verified by
   a)maxwell
   b)compton
   c)einstien
   d)davion and germar
3. What is the unit of absorbed dose?
   a)gray
   b)severt
   c)curie
   d)roentgen
4. The decay of neutron results into the formation of
   a)proton,positron
   b)proton,electron
   c)electron,anti neutrino
   d)proton,helium
5. The unit of concentration is
   a)mol. ml
   b)mol dm^-3
   c)gm equivalent lit^-1
   d)g. lit^-1
6. If there are weak intermolecular forces in a liquid, it will be
   a)more volatile
   b)more dense
   c)less volatile
   d)heavy dense
7. In the definition of conic the constant ratio is called
   a)directrix
   b)focus
   c)vertex
   d)eccentricity
8. Which sentence is correct?
   A. How beautiful moon is!
   B. How beautiful the moon is!
   C. How beautiful that moon is!
   D. How beautiful the moon is.
9. sugar crystals belong to the
   a)cubic
   b)monoclinic
   c)triclinic
   d)orthrorhombic
10. weber is a unit of
    a)magnetic flux
    b)magnetic flux density
    c)magnetic induction
    d)none of these