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You just finished Kinematics

In this chapter, you have completed: 19 concepts 17 doubts More than 30 Questions and Examples In this chapter, firstly you read Concepts of “Kinematics” and then moved to “applications of kinematics”. Apart from this, there are certain tips for you which will be helpful for you to develop a lot of interest in this chapter. There are some examples as well as practise question in each...

A projectile is thrown at an angle \beta with vertical .It reaches a maximum height H . The time taken to reach the highest point of its path is 

@Harshit As we have learned Time of Flight - Time for which projectile remains in the air above the horizontal plane. - wherein SO  Time taken to reach highest point =       Time taken to reach highest point = 

Equation of trajectory of a projectile is given by y = -x^2 +10 x , where x and y are in metres and x is along horizontal and y is vertically upward and particles is projected from origin .Then which of the following option is incorrect 

 

A.

Initial velocity of particle is \sqrt{505}m/s

B.

horizontal range is 10 m 

C.

Maximum range is 10 m 

D.

Angle of projection with horizontal is \tan ^{-1} (-1 )

505m/s
@Harshit Equation of path of a projectile - it is equation of parabola     Acceleratio due to gravity     initial velocity Angle of projection   - wherein Path followed by a projectile is parabolic is nature.     Compare this with    Maximum height H =       

A person A is moving along east and B is moving along north. Then relative velocity of A with respect to B is (V_{A}=10\, m/s\, ,\; V_{B}=10\sqrt{3}\, m/s)

    =    -      = 

A ball is thrown vertically upward with a velocity of 20 ms-1 from a top of a multistory  building.The hight of the  point from where  the ball is thrown is 25 m from the ground. The hight to which the ball rises from the ground and time taken before the ball hits the ground are (g:=10 ms-2)

  Maxmium height from the ground :20 + 25 = 45m Time to reach ground S=-25m, u=20 ms-1, a =-10 m/s2

Which of the following acts as a circuit protection device ? 

 

  • Option 1)

    conductor 

  • Option 2)

    inductor 

  • Option 3)

    switch 

  • Option 4)

    fuse 

fuse Option 1)conductor Option 2)inductor Option 3)switch Option 4)fuse 

In which of the following devices , the eddy current  effect is not used ? 

 

  • Option 1)

    induction furnace 

  • Option 2)

    magnetic braking in train 

  • Option 3)

    electromagnet 

  • Option 4)

    electric heater 

electric heater Option 1)induction furnace Option 2)magnetic braking in train Option 3)electromagnet Option 4)electric heater 

Pick the wrong answer in the context with rainbow 

 

  • Option 1)

    When the light rays undergo two internal  reflection in a water drop , a secondary rainbow is formed 

  • Option 2)

    The order of colors is reversed in the secondary rainbow 

  • Option 3)

    An observer can see a rainbow when his front is towards the sun 

  • Option 4)

    Rainbow is a combined effect of dispersion , refreaction and reflection of sunlight 

Rainbow can seen when back is towards the Sun.Option 1)When the light rays undergo two internal  reflection in a water drop , a secondary rainbow is formed Option 2)The order of colors is reversed in the secondary rainbow Option 3)An observer can see a rainbow when his front is towards the sun Option 4)Rainbow is a combined effect of dispersion , refreaction and reflection of sunlight 

A particle moving with velocity \vec V is acted by three forces shown by the vector triangle PQR . The velocity of the particle will : 

 

  • Option 1)

    increase 

  • Option 2)

    derease 

  • Option 3)

    remain constant 

  • Option 4)

    change acording to the smallest force QR 

 
Option 1) increase  Option 2) derease  Option 3) remain constant  Option 4) change acording to the smallest force QR 

Two parallel infinite line charges with linear charges densities + \lambda C/ m \: \: and \: \: - \lambda C/ m are placed at a distance  of 2R in free space . what is the electric field mid way between the two line charges ? 

  • Option 1)

    zero

  • Option 2)

    \frac{2 \lambda }{\pi \epsilon _0 R} N/C

  • Option 3)

    \frac{ \lambda }{\pi \epsilon _0 R} N/C

  • Option 4)

    \frac{\lambda }{2\pi \epsilon _0 R} N/C

 
Option 1) zero Option 2) Option 3) Option 4)

Two similar thin equiconvex lenses , of focal length f each , are kept  coaxially in contact  with each other such that the focal length of the combination is F_1 . When the space between the two lenses is filled  with glycerin  then the equivalent  focal length is F_2 . The ratio F_1 : F_2 

  • Option 1)

    2 : 1 

  • Option 2)

    1 : 2 

  • Option 3)

    2 : 3 

  • Option 4)

    3 : 4 

Option 1)2 : 1 Option 2)1 : 2 Option 3)2 : 3 Option 4)3 : 4 

The total energy of an electron in an atom in an orbit is -3.4 eV . Its kinetic and potential energies are respectively  

 

  • Option 1)

    -3.4 e V, -3.4 eV 

  • Option 2)

    -3.4 e V , - 6.8 e V 

  • Option 3)

    3.4 e V , - 6.8 e V 

  • Option 4)

    3.4 e V , 3.4 e V 

 
Option 1) -3.4 e V, -3.4 eV  Option 2) -3.4 e V , - 6.8 e V  Option 3) 3.4 e V , - 6.8 e V  Option 4) 3.4 e V , 3.4 e V 

A soap bubble , having radius of 1 mm is blown from, a detergent solution having a surface tension , of 2.5 \times 10 ^{-2 } N/m. The pressure inside the bubble equals at a point Z_0 below  the free surface of water in a container of water = 10 ^ 3 Kg / m ^ 3 , the value of Z_0 is 

  • Option 1)

    100 cm 

  • Option 2)

    10 cm 

  • Option 3)

    1 cm 

  • Option 4)

    0.5 cm 

Option 1)100 cm Option 2)10 cm Option 3)1 cm Option 4)0.5 cm 

The unit of thermal conductivity is : 

  • Option 1)

    JmK^{-1}

  • Option 2)

    Jm^{-1}K^{-1}

  • Option 3)

    WmK^{-1}

  • Option 4)

    Wm^{-1}K^{-1}

Option 1)Option 2)Option 3)Option 4)

A parallel palte capacitor of capacitance 20 \mu F is being charged by a voltage source whose potential is changing at the rate of 3 V/s . The conduction  current through the connecting wires , and the dispalcement  current through the plates of the capacitor , would be  resectively : 

 

  • Option 1)

    zero, 60 \mu A

  • Option 2)

    60 \mu A , 60 \mu A

  • Option 3)

    60 \mu A , zero

  • Option 4)

    zero , zero 

Option 1)zero, Option 2)Option 3)Option 4)zero , zero 

When a object is shot from the bottom of a long smooth inclined plane kept at an angle 60 \degree with horizontal , it can travel a distance x_1 along the plane . But when the inclination is decreased  to 30 \degree and the same object is shot with the same velocity , it can travelx_2 \: \: distance .\: \: Then\: \: x_1 : x_ 2 \: \: will\: \: be :

  • Option 1)

    1 : \sqrt 2

  • Option 2)

    \sqrt 2 : 1

  • Option 3)

    1 : \sqrt 3

  • Option 4)

    1 : 2 \sqrt 3

Option 1)Option 2)Option 3)Option 4)

A small hole of area of cross sectyion 2 mm ^ 2 is  present mear the botom  of a fully  filled open tank  of heiht 2 m . Taking g = 10 m /s ^2 , the rate of flow of water through the open hole would be nearly : 

 

  • Option 1)

    12.6 \times 10 ^{-6 } m^3 / s

  • Option 2)

    8.9 \times 10 ^{-6 } m^3 / s

  • Option 3)

    2.23 \times 10 ^{-6 } m^3 / s

  • Option 4)

    6.4 \times 10 ^{-6 } m^3 / s

 
  Option 1) Option 2) Option 3) Option 4)

A disc of radius 2 m and mass 100 Kg rolls on a horizontal floor . Its center of mass has speed of 20 cm/s . How much work is needed to stop it ? 

  • Option 1)

    3 J 

  • Option 2)

    30 Kj 

  • Option 3)

    2 J 

  • Option 4)

    1 J 

Option 1)3 J Option 2)30 Kj Option 3)2 J Option 4)1 J 

A force F  = 20 + 10 y acts on a particle in y - direction  where F  is in newton and y in meter  Work done by this force to move the particle from y = 0 to y = 1 is : 

  • Option 1)

    30 J 

  • Option 2)

    5 J 

  • Option 3)

    25 J 

  • Option 4)

    20 J 

Option 1)30 J Option 2)5 J Option 3)25 J Option 4)20 J 

A body weighs 200 N on the surface of the earth  how much will it weigh at half way down to the center of the earth ? 

 

  • Option 1)

    150 N 

  • Option 2)

    200 N 

  • Option 3)

    250 N 

  • Option 4)

    100 N 

 
Option 1) 150 N  Option 2) 200 N  Option 3) 250 N  Option 4) 100 N 
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