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Medical
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The bulk modulus of a spherical object is 'B'. If it is subjected to uniform to uniform pressure 'p', the fractional decrease in radius is:

  • Option 1)

    \frac{B}{3p}

  • Option 2)

    \frac{3p}{B}

  • Option 3)

    \frac{p}{3B}

  • Option 4)

    \frac{p}{B}

 
  Bulk Modulus - Ratio of normal stress to volumetric strain. v = Original  volume  = Change in volume P = Increase in pressure -ve(sign) shows volume  decrease. - wherein      or  Put this value in equation (i) we get fractional decrease in radius is Option 1) This solution is incorrect Option 2) This solution is incorrect Option 3) This solution is correct Option 4) This solution...
Medical
606 Views   |  

A  rope is wound around a hollow cylinder of mass 3 kg and radius 40 cm. What is the angluar acceleration of the cylinder if the rope is pulled with a force of 30 N?

  • Option 1)

    0.25\: rad/s^{2}

  • Option 2)

    25\: rad/s^{2}

  • Option 3)

    5\: m/s^{2}

  • Option 4)

    25 m/s^{2}

 
As we learnt in Torque -       - wherein This can be calculated by using either  = perpendicular distance from origin to the line of force. = component of force perpendicular to line joining force.       and,   Analogue of second law of motion for pure rotation - - wherein Torque equation can be applied only about two point (i) centre of motion. (ii) point which has zero...
Medical
107 Views   |  

If \Theta _{1} and \Theta _{2} be the apparent angles of dip observed in two verical planes at right angles to each other, then the true angle of  dip \Theta is given by:-

  • Option 1)

    \tan ^{2}\Theta =\tan ^{2}\Theta _{1}+\tan ^{2}\Theta _{2}

  • Option 2)

    \cot ^{2}\Theta =\cot ^{2}\Theta _{1}-\cot ^{2}\Theta _{2}

  • Option 3)

    \tan ^{2}\Theta =\tan ^{2}\Theta _{1}-\tan ^{2}\Theta _{2}

  • Option 4)

    \cot ^{2}\Theta =\cot ^{2}\Theta _{1}+\cot ^{2}\Theta _{2}

 
  Angle of Inclination or Dip - It is the angle between the direction of intensity of total magnetic field of earth and a horizontal line in the magnetic meridian. -     CO+ Option 1) This solution is incorrect  Option 2) This solution is incorrect  Option 3) This solution is incorrect  Option 4) This solution is correct 
Medical
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A 250-turn rectangular coil of length 2.1cm and width 1.25cm carries a current of 85\mu A and subjected to magnetic field of strength 0.85T. Work done for rotating the coil by 180^{o} against the torque is

  • Option 1)

    4.55\mu j

  • Option 2)

    2.3\mu j

  • Option 3)

    1.15\mu j

  • Option 4)

    9.1\mu j

 
As we learnt  Work done by current carrying coil - -    work done = NIAB (1-) N = 250, A= L X b    2.1 cm X 1.25 cm   ,       ,      Option 1) 4.55 Incorrect Option Option 2) 2.3 Incorrect Option Option 3) 1.15 Incorrect Option Option 4) 9.1 Correct Option
Medical
117 Views   |  

A long solenoid of diameter 0.1m has 2\times 10^{4} turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0A from 4A in 0.05s.  If the resistance of the coil is 10\pi ^{2}\Omega. the total charge flowing through the coil during this time is:

  • Option 1)

    16\mu C

  • Option 2)

    32\mu C

  • Option 3)

    16 \pi \mu C

  • Option 4)

    32 \pi \mu C

 
  Faraday Second Law of Induction emf - -     Option 1) 16 This is incorrect option Option 2) 32 This is correct option Option 3) 16 This is incorrect option Option 4) 32 This is incorrect option
Medical
95 Views   |  

In an electromagnetic wave in free space the root mean square value of the electric field is E_{rms}=6V/m. The peak value of the magnetic field is:-

  • Option 1)

    2.83\times 10^{-8}T

  • Option 2)

    0.70\times 10^{-8}T

  • Option 3)

    4.23\times 10^{-8}T

  • Option 4)

    1.41\times 10^{-8}T

 
As we learnt in  Relation between Eo and Bo - - wherein = Electric field amplitude = Magnetic field amplitude C= Speed of light in vacuum    Erms=6 V/m peak value   magneitc field peak value  Option 1) Correct Option 2) Incorrect Option 3) Incorrect Option 4) Incorrect
Medical
87 Views   |  

A physical quantity of the dimensions of length that can be formed out of c, G and \frac{e^{2}}{4\pi \varepsilon _{o}} is (c is velocity of light, G is universal constant of gravitation and e is charge)  

  • Option 1)

    c^{2}\left [ G\frac{e^{2}}{4\pi \varepsilon _{o}} \right ]^{\frac{1}{2}}

  • Option 2)

    \frac{1}{c^{2}}\left [ \frac{e^{2}}{G4\pi \varepsilon _{o}} \right ]^{\frac{1}{2}}

  • Option 3)

    \frac{1}{c}G\frac{e^{2}}{4\pi \varepsilon _{o}}

  • Option 4)

    \frac{1}{c^{2}}\left [ G\frac{e^{2}}{4\pi \varepsilon _{o}} \right ]^{\frac{1}{2}}

 
As we learnt in Time period of a simple pendulam - Equating exponents of similar quantities a=0     b=1/2    c=-1/2 - wherein     on comparing both sides we get   Option 1) Incorrect Option 2) Incorrect Option 3) Incorrect Option 4) Correct
Medical
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Two discs of same moment of inertia rotating about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities \omega1 and \omega2. They are brought into contact face to face coinciding the axis of rotation. The expression for loss of energy during this process is:

  • Option 1)

    \frac{1} {2}\text{I}\left( {\omega _1 + \omega _2 } \right)^2

  • Option 2)

    \frac{1} {4}\text{I}\left( {\omega _1 - \omega _2 } \right)^2

  • Option 3)

    \text{I}\left( {\omega _1 - \omega _2 } \right)^2

  • Option 4)

    \frac{\text{I}} {\text{8}}\left( {\omega _1 - \omega _2 } \right)^2

 
Resolving power   Law of conservation of angular moment - - wherein If net torque is zero i.e. angular momentum is conserved only when external torque is zero .   Loss in K.E =  Option 1) This option is incorrect Option 2) This option is correct. Option 3) This option is correct Option 4) This option is incorrect
Medical
216 Views   |  

Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time t1. On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time t2. The time taken by her to walk up on the moving escalator will be:

  • Option 1)

    \frac{t_{1}t_{2}}{t_{2}-t_{1}}

  • Option 2)

    \frac{t_{1}t_{2}}{t_{2}+t_{1}}

  • Option 3)

    t_{1}-t_{2}

  • Option 4)

    \frac{t_{1}+t_{2}}{2}

 
As we learnt in Case of Relative velocity - When A & B are moving along with straight line in opposite direction.  Velocity of object A.  Velocity of object B. Relative velocity of A with respect to B is.   is because of opposite direction.     - wherein E.g A body moves in east with speed of 20m-1, And body in west with velocity of 5ms-1. Find velocity of A with respect to B. = (20+5 )...
Medical
110 Views   |  

Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is (e + \Deltae). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then \Deltae is of the order of [Given mass of hydrogen mh = 1.67 x 10-27 kg]

  • Option 1)

    10-20 C

  • Option 2)

    10-23 C

  • Option 3)

    10-37 C

  • Option 4)

    10-47 C

 
As we learnt in  Coulombic force - - wherein K - proportionality Constant  Q1 and Q2 are two Point charge    Charge on one hydrogen atoms gravitational force between two hydrogen 2f force on the system is 2ro   Option 1) 10-20 C Incorrect Option 2) 10-23 C Incorrect Option 3) 10-37 C Correct Option 4) 10-47 C
Medical
309 Views   |  

Two cars moving in opposite directions approach each other with speed of 22 m/s and 16.5 m/s respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is [velocity of sound 340 m/s]:

  • Option 1)

    350 Hz

  • Option 2)

    361 Hz

  • Option 3)

    411 Hz

  • Option 4)

    448 Hz

 
As we learnt in Frequency of sound when source and observer are moving towards each other -   - wherein Speed of sound Speed of observer speed of source Original frequency apparent frequency     Option 1) 350 Hz This option is incorrect. Option 2) 361 Hz This option is incorrect. Option 3) 411 Hz This option is incorrect. Option 4) 448 Hz This option is correct.
Medical
96 Views   |  

One end of string of length 1  is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed v, the net force on the particle (directed towards centre) will be (T represents the tension in the string)

  • Option 1)

    T+\frac{mv^{2}}{1}

  • Option 2)

    T-\frac{mv^{2}}{1}

  • Option 3)

    zero

  • Option 4)

    T

 
As we learnt in  Centripetal Force - F = Centripetal force  Angular velocity n = frequency - wherein Force acts on the body along the radius and towards centre.     F is net force acting on particle. Option 1) Correct Option 2) Incorrect Option 3) zero Incorrect Option 4) T Incorrect
Medical
1207 Views   |  

Two blocks A and B of masses 3m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively:

 

  • Option 1)

     

    \frac{\text{g}} {3}\text{,g}

  • Option 2)

    g, g

  • Option 3)

    \frac{g}{3},\: \frac{g}{3}

  • Option 4)

    g, \frac{g}{3}

 
As we learnt in  Reaction or Normal Force - A force which is perpendicular to the surface in contact. - wherein                          Before cut Kx = 4mg After cut T=0 Option 1)   Incorrect Option 2) g, g Correct Option 3) Incorrect Option 4) Incorrect
Medical
99 Views   |  

A gas mixture consists of 2 moles of O2 and 4 moles of Ar at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

  • Option 1)

    4 RT

  • Option 2)

    15 RT

  • Option 3)

    9 RT

  • Option 4)

    11 RT

 
As we learnt in Total internal energy -   - wherein Change in internal energy (Always) is degree of freedom     Internal energy of a system is    or     Correct option is 4.   Option 1) 4 RT This solution is incorrect. Option 2) 15 RT This solution is incorrect. Option 3) 9 RT This solution is incorrect. Option 4) 11 RT This solution is correct.
Medical
100 Views   |  

A Carnot engine having an efficiency of \frac{1} {10} as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is :

  • Option 1)

    1 J

  • Option 2)

    90 J

  • Option 3)

    99 J

  • Option 4)

    100 J

 
As we learnt in Coefficient of performance (beta) -   - wherein For a perfect refrigerator     Efficiency of a carnot cycle -   are in kelvin   - wherein Source temperature Sink Temperature    For a carnot cycle = Coefficient of performance = Efficiency of carnot engine   Option 1) 1 J This option is incorrect. Option 2) 90 J This option is correct. Option 3) 99 J This option...
Medical
571 Views   |  

The x and y coordinates of the particle at any time are x = 5t - 2t2 and y = 10t respectively, where x and y are in meters and t in seconds. The acceleration of the particle at t = 2s is

  • Option 1)

    0

  • Option 2)

    5m /s2

  • Option 3)

    -4m /s2

  • Option 4)

    -8m /s2

 

Answer is 3rd option

Medical
525 Views   |  

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that 8th bright fringe in the medium lies where 5th dark fringe lies in air. The refractive index of the medium is nearly:

  • Option 1)

    1.25

  • Option 2)

    1.59

  • Option 3)

    1.69

  • Option 4)

    1.78

 
As we learnt in Fringe Width in a medium - - wherein Since wavelength in a medium become       Fringe width in air = Fringe width in any other medium = According to question or  Option 1) 1.25 Incorrect Option 2) 1.59 Incorrect Option 3) 1.69 Incorrect Option 4) 1.78 Correct
Medical
717 Views   |  

Two Polaroids P1 and P2 are placed with their axis perpendicular to each other. Unpolarised light I0 is incident on P1. A third polaroid P3 is kept in between P1 and P2 such that its axis makes an angle 45° with that of P1 . The intensity of transmitted light through P2 is:

  • Option 1)

    \frac{{\text{I}_0 }} {2}

  • Option 2)

    \frac{{\text{I}_0 }} {4}

  • Option 3)

    \frac{{\text{I}_0 }} {8}

  • Option 4)

    \frac{{\text{I}_0 }} {16}

 
As we learnt in Malus Law - angle made by E vector with transmission axis. - wherein Intensity of transmitted light after polarisation . Intensity of  incident light.       Intensity of light after crossing  Intensity of light after crossing  Intensity of light after crossing   Option 1) Incorrect Option 2) Incorrect Option 3) Correct Option 4) Incorrect
Medical
537 Views   |  

A thin prism having refracting angle 10° is made of glass of refractive index 1.42. This prism is combined with another thin prism of glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be :

  • Option 1)

  • Option 2)

  • Option 3)

  • Option 4)

    10°

 
As we learnt in Condition for deviation without dispersion - - wherein = Refractive index of violet ( prism 1) Refractive index of red ( prism 1) = Refractive index of violet ( prism 2) Refractive index of red ( prism 2)       For dispersion without deviation  Option 1) 4° This option is incorrect  Option 2) 6° This option is correct  Option 3) 8° This option is incorrect  Option...
Medical
722 Views   |  

A person can see clearly objects only when they lie between 50 cm and 400 cm from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use, will be

  • Option 1)

    convex, + 2.25 diopter

  • Option 2)

    concave, - 0.25 diopter

  • Option 3)

    concave, - 0.2 diopter

  • Option 4)

    convex, + 0.15 diopter

 
As we learnt in Optical power of a mirror -   - wherein focal length with sign and is in meters unit of power = diopter       This person wants to increase the farther distance from 400 cm to . Hence he must use a lense who will form image of an object which is place at infinity to 400 cm. Hence focal length of the lens = 400 cm. It must be concave  P =  =    Option 1) convex, + 2.25...
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