Physics-
General
Easy
Question
Curves in the graph shown give, as functions of radial distance r, the magnitude B of the magnetic field inside and outside four long wires a, b, c and d, carrying currents that are uniformly distributed across the cross– sections of the wires. Overlapping portions of the plots are indicated by double labels
The current density in wire a is
- greater than in wire c
- less than in wire c
- equal to that in wire c
- not comparable to that of in wire c due to lack of information
The correct answer is: greater than in wire c
Related Questions to study
physics-
Curves in the graph shown give, as functions of radial distance r, the magnitude B of the magnetic field inside and outside four long wires a, b, c and d, carrying currents that are uniformly distributed across the cross– sections of the wires. Overlapping portions of the plots are indicated by double labels
Which wire has the greatest magnitude of the magnetic field on the surface ?
Curves in the graph shown give, as functions of radial distance r, the magnitude B of the magnetic field inside and outside four long wires a, b, c and d, carrying currents that are uniformly distributed across the cross– sections of the wires. Overlapping portions of the plots are indicated by double labels
Which wire has the greatest magnitude of the magnetic field on the surface ?
physics-General
physics-
Curves in the graph shown give, as functions of radial distance r, the magnitude B of the magnetic field inside and outside four long wires a, b, c and d, carrying currents that are uniformly distributed across the cross– sections of the wires. Overlapping portions of the plots are indicated by double labels
Which wire has the greatest radius?
Curves in the graph shown give, as functions of radial distance r, the magnitude B of the magnetic field inside and outside four long wires a, b, c and d, carrying currents that are uniformly distributed across the cross– sections of the wires. Overlapping portions of the plots are indicated by double labels
Which wire has the greatest radius?
physics-General
physics-
The following experiment was performed by J.J.Thomson in order to measure the ratio of the charge e to the mass m of an electron. Figure shows a modern version of Thomson's apparatus. Electrons emitted from a hot filament and accelerated by a potential difference V. As the electrons pass through the deflector plates, they encounter both electric and magnetic fields. When the electrons leave the plates they enter a field–free region that extends to the fluorescent screen. The beam of electrons can be observed as a spot of light on the screen. The entire region in which the electrons travel is evacuated with a vacuum pump.
Thomson's procedure was to first set both the electric and magnetic fields to zero, note the position of the undeflected electron beam on the screen, then turn on only the electric field and measure the resulting deflection. The deflection of an electron in an electric field of magnitude E is given by 
, where L is the length of the deflecting plates, and v is the speed of the electron. The deflection d1
can also be calculated from the total deflection of the spot on the screen, 
, and the geometry of the apparatus. In the second part of the experiment Thomson adjusted the magnetic field so as to exactly cancel the force applied by the electric field, leaving the electron beam undeflected. This gives 
By combining this relation with the expression for d1 one can calculate the charge to mass ratio of the electron as a function of the known quantities. The result is 
Why was it important for Thomson to evacuate the air from the apparatus ?
The following experiment was performed by J.J.Thomson in order to measure the ratio of the charge e to the mass m of an electron. Figure shows a modern version of Thomson's apparatus. Electrons emitted from a hot filament and accelerated by a potential difference V. As the electrons pass through the deflector plates, they encounter both electric and magnetic fields. When the electrons leave the plates they enter a field–free region that extends to the fluorescent screen. The beam of electrons can be observed as a spot of light on the screen. The entire region in which the electrons travel is evacuated with a vacuum pump.
Thomson's procedure was to first set both the electric and magnetic fields to zero, note the position of the undeflected electron beam on the screen, then turn on only the electric field and measure the resulting deflection. The deflection of an electron in an electric field of magnitude E is given by , where L is the length of the deflecting plates, and v is the speed of the electron. The deflection d1
can also be calculated from the total deflection of the spot on the screen, , and the geometry of the apparatus. In the second part of the experiment Thomson adjusted the magnetic field so as to exactly cancel the force applied by the electric field, leaving the electron beam undeflected. This gives By combining this relation with the expression for d1 one can calculate the charge to mass ratio of the electron as a function of the known quantities. The result is
Why was it important for Thomson to evacuate the air from the apparatus ?
physics-General
physics-
In the given circuit having an ideal inductor of inductance L, resistor of resistance R and an ideal cell of emf 
the work done by the battery in one time constant after the switch is closed is
In the given circuit having an ideal inductor of inductance L, resistor of resistance R and an ideal cell of emf the work done by the battery in one time constant after the switch is closed is
physics-General
physics-
A circuit containing capacitors 
and 
as shown in the figure are in steady state with key 
closed. At the instant t = 0, if is opened and 
is closed then the maximum current in the circuit will be :
A circuit containing capacitors and as shown in the figure are in steady state with key closed. At the instant t = 0, if is opened and is closed then the maximum current in the circuit will be :
physics-General
physics-
A small circular wire loop of radius a is located at the centre of a much larger circular wire loop of radius b as shown above
Both loops are coaxial and coplanar. The larger loop carries a time (t) varying current 
cos 
t, where 
and are constants. The magnetic field generated by the current in the large loop induces in the small loop an emf that is approximately equal to which of the following.
A small circular wire loop of radius a is located at the centre of a much larger circular wire loop of radius b as shown aboveBoth loops are coaxial and coplanar. The larger loop carries a time (t) varying current cos t, where and are constants. The magnetic field generated by the current in the large loop induces in the small loop an emf that is approximately equal to which of the following.
physics-General
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A conducting circular ring and a conducting elliptical ring both are moving pure translationally in a uniform magnetic field of strength B as shown in figure on a horizontal conducting plane then potential difference between top most points of circle and ellipse is :
A conducting circular ring and a conducting elliptical ring both are moving pure translationally in a uniform magnetic field of strength B as shown in figure on a horizontal conducting plane then potential difference between top most points of circle and ellipse is :
physics-General
physics-
A current flows through a rectangular conductor in the presence of uniform magnetic field B pointing out of the page as shown. Then the potential difference VP – VQ is equal to. (assume charge carriers in the conductor to be positively charged moving with a drift velocity of v)
A current flows through a rectangular conductor in the presence of uniform magnetic field B pointing out of the page as shown. Then the potential difference VP – VQ is equal to. (assume charge carriers in the conductor to be positively charged moving with a drift velocity of v)
physics-General
physics-
The plane of a square loop of wire with edge length a = 0.2 m is perpendicular to the earth's magnetic field BE at a point where BE = 15 
T. The total resistance of the loop and the wires connecting it to the galvanometer is 0.5 
. If the loop is suddenly collapsed (such that area of the loop becomes zero) by horizontal forces as shown, the total charge passing through the galvanometer is :
The plane of a square loop of wire with edge length a = 0.2 m is perpendicular to the earth's magnetic field BE at a point where BE = 15 T. The total resistance of the loop and the wires connecting it to the galvanometer is 0.5 . If the loop is suddenly collapsed (such that area of the loop becomes zero) by horizontal forces as shown, the total charge passing through the galvanometer is :
physics-General
physics-
Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance 1 /m. Position of the conducting rod at t = 0 is shown. A time t dependent magnetic field B = 2t Tesla is switched on at t = 0
At t = 0, when the magnetic field is switched on, the conducting rod is moved to the left at constant speed 5 cm/s by some external means. The rod moves remaining perpendicular to the rails. At t = 2s, induced emf has magnitude.
Figure shows a conducting rod of negligible resistance that can slide on smooth U-shaped rail made of wire of resistance 1 /m. Position of the conducting rod at t = 0 is shown. A time t dependent magnetic field B = 2t Tesla is switched on at t = 0
At t = 0, when the magnetic field is switched on, the conducting rod is moved to the left at constant speed 5 cm/s by some external means. The rod moves remaining perpendicular to the rails. At t = 2s, induced emf has magnitude.
physics-General
physics-
A particle is projected up an inclined as shown in figure. For maximum range over the inclined plane, the value of 
should be
A particle is projected up an inclined as shown in figure. For maximum range over the inclined plane, the value of should be
physics-General
physics-
The velocity-time graph of a body moving along a straight line is as follows:
The displacement of the body in 5 s is
The velocity-time graph of a body moving along a straight line is as follows:
The displacement of the body in 5 s is
physics-General
physics-
The velocity-time graph of a body is given below.
The maximum acceleration in 
is
The velocity-time graph of a body is given below.
The maximum acceleration in is
physics-General
physics-
From the velocity – time graph given of a particle moving in a straight line, one can conclude that
From the velocity – time graph given of a particle moving in a straight line, one can conclude that
physics-General
physics-
A particle a is projected form the ground with an initial velocity of 10 m/s at an angle of 60° with horizontal. From what height h should an another particle B be projected horizontal with velocity 5 m/s so that both the particles collides at point C if both are projected simultaneously 
A particle a is projected form the ground with an initial velocity of 10 m/s at an angle of 60° with horizontal. From what height h should an another particle B be projected horizontal with velocity 5 m/s so that both the particles collides at point C if both are projected simultaneously
physics-General
