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Who noticed the deflection of the compass needle every time the current was passed through the wire? When an electric current flows through a wire, it behaves like a magnet.

Hans Christian Oersted was the first person who noticed the deflection of the compass needle every time the current was passed through the wire. When an electric current flows through a wire, it behaves like a magnet.
It can be done by Connecting a large Resistance R in series with the Galvanometer

By connecting a high resistance in series with the galvanometet

pressure inside a liquid jet in excess of atmostpheric pressure . for example if aglass tube of samll diameter is partially immersed in water , the water will wet the surface of the tube ant it will rise in the tube to some height above the normal water surface . In this case, the water surface is concave upward.

 

  • In this collision (K.E)_{initial} \neq (K.E.)_{final}

  • Coefficient of restitution 0 < e < 1 

  • As (K.E)_{initial} > (K.E.)_{final}

The loss in kinetic energy appears in other forms, such as heat, sound etc. 

Ex- Collision between two billiard balls. All majority of collision belong to this category.

in inelastic collision k. e. is conserved

If not then the loss in kinetic energy is transferred into which form of energy??

Work

 

Physics has many definitions. In simple words Physics is branch of science concerned with the nature and properties of matter and energy

phsiyics is consist of all kind of physical property   

Two particles move at right angle to each other de Broglie wavelengths as \lambda_1 and \lambda_2, particle suffers a perfectly inelastic collision. The de Broglie wavelength \lambda of final particle is given by

  • Option 1)

    \lambda=\frac{\lambda _{1}\lambda _{2}}{\sqrt{\lambda_{1}^{2}+\lambda_{2}^{2}}}

  • Option 2)

    \lambda=2\frac{\lambda _{1}\lambda _{2}}{\sqrt{\lambda_{1}^{2}+\lambda_{2}^{2}}}

  • Option 3)

    \lambda=\frac{\lambda _{1}^2\lambda _{2}}{\sqrt{\lambda_{1}^{2}+\lambda_{2}^{2}}}

  • Option 4)

    \lambda=\frac{\lambda _{1}\lambda _{2}}{2\sqrt{\lambda_{1}^{2}+\lambda_{2}^{2}}}

 

option 3

 

An interference experiment ratio of amplitude of coherent waves is . What is the ratio of maximum and minimum intensities of frings?

  • Option 1)

    1

  • Option 2)

    2

  • Option 3)

    3

  • Option 4)

    4

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

What is time at which the rate of dissipation is equal to the rate at which magnetic energy stored in the inductor?

  • Option 1)

    1.4 sec

  • Option 2)

    1.9 sec

  • Option 3)

    5 sec

  • Option 4)

    0.03 sec

option 3

 

Plane electromagnetic wave travelled in x-direction has electric field component E = 6V/m which is in y-direction. Corresponding Magnetic field component (B) is-

  • Option 1)

    B_0=2*10^{-8}T (in \ \ z-axis)

  • Option 2)

    B_0=6*10^{-8}T (in \ \ z-axis)

  • Option 3)

    B_0=12*10^{-8}T (in \ \ z-axis)

  • Option 4)

    B_0=2*10^{8}T (in \ \ z-axis)

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

Bob at pendulum mass 2g, charge , an electric field of intensity 2000v/m. Angle of pendulum with vertical at equilibrium?

  • Option 1)

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

  • Option 2)

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

  • Option 3)

    \Theta = sin^{-1}{\frac{1}{2}}

  • Option 4)

    \Theta = tan^{-1}{\frac{1}{4}}

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

Consider a Steel wire of radius= 2mm of a load equal to 4 kg to be suspended from a rigid support and its top end, such that it is in hanging in a vertical position. What is its tensile stress due to its own weight? (take g=3.1 \pi ms^{-2} )

  • Option 1)

    6.2*10^{6} Nm^2

  • Option 2)

    3.1*10^{-6} Nm^2

  • Option 3)

    3.1*10^{6} Nm^2

  • Option 4)

    3.1*10^{5} Nm^2

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

If   gas molecules each of mass Kg collide over the area of   in unit second with  Speed , the pressure exerted will be?

  • Option 1)

    3Nm^{2}

  • Option 2)

    2 \ Nm^2

  • Option 3)

    4Nm^{2}

  • Option 4)

    6Nm^{2}

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

In SI units, the dimension of is

  • Option 1)

  • Option 2)

    M^{-1}L^{2}T^{3}A

  • Option 3)

    M^{-1}L^{2}T^{5}A^{2}

  • Option 4)

    M^{-1}L^{2}T^{-3}A

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

Moment of inertia of a body about a given axis is 1.5\:kg\:m^{2}. Initially the body is ate rest. In order to produce a rotational kinetic energy of 1200\:J , the angular acceleration of 20\:rad/s^{2} must be applied about the axis for a duration of :

  • Option 1)

    2.5\:s

  • Option 2)

    2\:s

  • Option 3)

    5\:s

  • Option 4)

    3\:s

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

In a conductor , if the number of conduction electron per unit volume is 8.5\times 10^{28}m^{-3}  and mean free time is 25\:fs ( femto second ) , it's approximate resistivity is : 

(m_{e}=9.1\times10^{-31}kg)

  • Option 1)

    10^{-6}\:\:\Omega\:m

  • Option 2)

    10^{-7}\:\:\Omega\:m

  • Option 3)

    10^{-8}\:\:\Omega\:m

  • Option 4)

    10^{-5}\:\:\Omega\:m

 
    Resistivity - - wherein It is independent of shape and size of the body i.e.  and      we know that , Option 1) Option 2) Option 3) Option 4)

A message signal of frequency 100 MHz and peak voltage 100V is used to execute amplitude

modulation on a carrier wave of frequency 300 GHz and peak voltage 400V. The modulation 

index and difference between the two side band frequencies are:

  • Option 1)

    4;1\times 10^{8}\: Hz

  • Option 2)

    4;2\times 10^{8}\: Hz

  • Option 3)

    0.25;2\times 10^{8}\: Hz

  • Option 4)

    0.25;1\times 10^{8}\: Hz

  Modulation Index - The ratio of change of amplitude of carrier wave to the amplitude of original carrier wave. - wherein     Side band frequency - AM wave contains three frequency   - wherein is carrier frequency, are side band frequency.     Band Width - The two side band lie on either side of the carrier frequency at equal frequency intravel, fm - wherein...

A ball is thrown upward with an initial velocity V_{o} from the surface of the earth.

The motion of the ball is affected by a drag force equal to m\gamma v^{2} ( where m is 

mass of the ball, v is its instataneous velocity and \gamma is a constant). Time taken

by the ball to rise to its zenith is:

  • Option 1)

    \frac{1}{\sqrt{\gamma g}}\tan^{-1}(\sqrt{\frac{\gamma }{g}}V_{o})

  • Option 2)

    \frac{1}{\sqrt{\gamma g}}\sin^{-1}(\sqrt{\frac{\gamma }{g}}V_{o})

  • Option 3)

    \frac{1}{\sqrt{\gamma g}}\ln(1+\sqrt{\frac{\gamma }{g}}V_{o})

  • Option 4)

    \frac{1}{\sqrt{2\gamma g}}\tan^{-1}(\sqrt{\frac{2\gamma }{g}}V_{o})

 
  Newton's 2nd Law -     Therefore   - wherein  in C.G.S & S.I Force can be defined as rate of change of momentum.     =>  =>  Option 1) Option 2) Option 3) Option 4)

A submarine experiance a pressure of 5.05\times 10^{6}Pa at a depth of  d_{1} in a sea . When it goes further to a depth of d_{2}, it experiences a pressure of 8.08\times 10^{6}Pa .Then d_{2}-d_{1} is approximately (density of water =10^{3}Kg/m^{3}and acceleration due to gravity =10ms^{-2}):
 

 

 

 

 

 

  • Option 1)

    300m

  • Option 2)

    400m

  • Option 3)

    600m

  • Option 4)

    500m

 
    Absolute Pressure -   - wherein     Option 1) 300m Option 2) 400m Option 3) 600m Option 4) 500m

At 40^{\circ}C, a brass wire of 1 mn radius is hung from the ceiling. A small mass, M is hung from the free end of the wire. When the wire is cooled down from 40^{\circ}C to 20^{\circ}C it regains its original length of 0.2 m. The value of M is close to :

( Coefficient of linear expansion and Young's modulus of brass are 10^{-5}/^{\circ}C and 10^{11}N/m^{2}, respectively ; g=10ms^{-2})

  • Option 1)

    9kg

  • Option 2)

    0.9kg

  • Option 3)

    1.5kg

  • Option 4)

    0.5kg

 
also we know  As  is closet to  hence option (1) is correct Option 1) Option 2) Option 3) Option 4)
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