Physics-
General
Easy
Question
A steady current is set up in a cubic network composed of wires of equal resistance and length d as shown in figure. What is the magnetic field at the centre of cube P due to the cubic network ?
- 0
The correct answer is: 0
By symmetry, the magnetic field at the centre P is zero.
Related Questions to study
physics-
Two infinitely long linear conductors are arranged perpendicular to each other and are in mutually perpendicular planes as shown in figure. If 
along the y-axis and 
along negative z-axis and AP = AB = 1 cm. The value of magnetic field strength
Two infinitely long linear conductors are arranged perpendicular to each other and are in mutually perpendicular planes as shown in figure. If along the y-axis and along negative z-axis and AP = AB = 1 cm. The value of magnetic field strength
physics-General
physics-
An infinitely long wire carrying current I is along Y axis such that its one end is at point A (0, b) while the wire extends up to + 
. The magnitude of magnetic field strength at point (a, 0) is
An infinitely long wire carrying current I is along Y axis such that its one end is at point A (0, b) while the wire extends up to + . The magnitude of magnetic field strength at point (a, 0) is
physics-General
physics-
The magnetic field at the origin due to the current flowing in the wire as shown in figure below is
The magnetic field at the origin due to the current flowing in the wire as shown in figure below is
physics-General
physics-
If the magnetic field at 'P' in the given figure can be written as K tan 
then K is
If the magnetic field at 'P' in the given figure can be written as K tan then K is
physics-General
physics-
In the figure shown ABCDEFA was a square loop of side 
, but is folded in two equal parts so that half of it lies in xz plane and the other half lies in the yz plane. The origin 'O' is centre of the frame also. The loop carries current ' i '. The magnetic field at the centre is:
In the figure shown ABCDEFA was a square loop of side , but is folded in two equal parts so that half of it lies in xz plane and the other half lies in the yz plane. The origin 'O' is centre of the frame also. The loop carries current ' i '. The magnetic field at the centre is:
physics-General
physics-
The negatively and uniformly charged nonconducting disc as shown in the figure is rotated clockwise with great angular speed. The direction of the magnetic field at point A in the plane of the disc is
The negatively and uniformly charged nonconducting disc as shown in the figure is rotated clockwise with great angular speed. The direction of the magnetic field at point A in the plane of the disc is
physics-General
physics-
In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l, w and d, respectively. A uniform magnetic field B 
is applied on the strip along the positive y-direction. Due to this, the charge carries experience a net deflection along the z-direction. This results in accumulation of charge caries on the surface PQRS and appearance of equal and opposite charges on the face opposite to PQRS. A potential difference along the z-direction is thus developed. Charge accumulation continues until the magnetic force is balanced by the electric force. The current is assumed to be uniformly distributed on the cross section of the strip and carried by electrons.
Consider two different metallic strips (1 and 2) of same dimensions (length l, width w and thickness d) with carrier densities 
and 
, respectively. Strip 1 is placed in magnetic field 
and strip 2 is placed in magnetic field 
, both along positive y-directions. Then 
and 
are the potential differences developed between K and M in strips 1 and 2, respectively. Assuming that the current I is the same for both the strips, the correct option (S) is (are).
In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l, w and d, respectively. A uniform magnetic field B is applied on the strip along the positive y-direction. Due to this, the charge carries experience a net deflection along the z-direction. This results in accumulation of charge caries on the surface PQRS and appearance of equal and opposite charges on the face opposite to PQRS. A potential difference along the z-direction is thus developed. Charge accumulation continues until the magnetic force is balanced by the electric force. The current is assumed to be uniformly distributed on the cross section of the strip and carried by electrons.
Consider two different metallic strips (1 and 2) of same dimensions (length l, width w and thickness d) with carrier densities and , respectively. Strip 1 is placed in magnetic field and strip 2 is placed in magnetic field , both along positive y-directions. Then and are the potential differences developed between K and M in strips 1 and 2, respectively. Assuming that the current I is the same for both the strips, the correct option (S) is (are).
physics-General
physics-
In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l, w and d, respectively. A uniform magnetic field B is applied on the strip along the positive y-direction. Due to this, the charge carries experience a net deflection along the z-direction. This results in accumulation of charge caries on the surface PQRS and appearance of equal and opposite charges on the face opposite to PQRS. A potential difference along the z-direction is thus developed. Charge accumulation continues until the magnetic force is balanced by the electric force. The current is assumed to be uniformly distributed on the cross section of the strip and carried by electrons.
Consider two different metallic strips (1 and 2) of the same material. Their lengths are the same, widths are 
and 
and thicknesses are 
and 
, respectively. Two points K and M are symmetrically located on the opposite faces parallel to the x-y plane (see figure). and are the potential differences between K and M in strips 1 and 2 , respectively. Then, for a given current I flowing through them in a given magnetic field strength B, the correct statement(s) is (are).
In a thin rectangular metallic strip a constant current I flows along the positive x-direction, as shown in the figure. The length, width and thickness of the strip are l, w and d, respectively. A uniform magnetic field B is applied on the strip along the positive y-direction. Due to this, the charge carries experience a net deflection along the z-direction. This results in accumulation of charge caries on the surface PQRS and appearance of equal and opposite charges on the face opposite to PQRS. A potential difference along the z-direction is thus developed. Charge accumulation continues until the magnetic force is balanced by the electric force. The current is assumed to be uniformly distributed on the cross section of the strip and carried by electrons.
Consider two different metallic strips (1 and 2) of the same material. Their lengths are the same, widths are and and thicknesses are and , respectively. Two points K and M are symmetrically located on the opposite faces parallel to the x-y plane (see figure). and are the potential differences between K and M in strips 1 and 2 , respectively. Then, for a given current I flowing through them in a given magnetic field strength B, the correct statement(s) is (are).
physics-General
physics-
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If 
is larger than , which of the following graphs shows the correct variation of R with T in these fields? Electrical resistance of certain materials, known as superconductors, changes abruptly from a nonzero value to zero as their temperature is lowered below a critical temperature 
(0). An interesting property of superconductors is that their critical temperature becomes smaller than (0) if they are placed in a magnetic field, i.e., the critical temperature (B) is a function of the magnetic field strength B. The dependence of (B) on B is shown in the figure.
A superconductor has (0) = 100 K. When a magnetic field of 7.5 Tesla is applied, its decreases to 75 K. For this material one can definitely say that when
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields? Electrical resistance of certain materials, known as superconductors, changes abruptly from a nonzero value to zero as their temperature is lowered below a critical temperature (0). An interesting property of superconductors is that their critical temperature becomes smaller than (0) if they are placed in a magnetic field, i.e., the critical temperature (B) is a function of the magnetic field strength B. The dependence of (B) on B is shown in the figure.
A superconductor has (0) = 100 K. When a magnetic field of 7.5 Tesla is applied, its decreases to 75 K. For this material one can definitely say that when
physics-General
physics-
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields? Electrical resistance of certain materials, known as superconductors, changes abruptly from a nonzero value to zero as their temperature is lowered below a critical temperature (0). An interesting property of superconductors is that their critical temperature becomes smaller than (0) if they are placed in a magnetic field, i.e., the critical temperature (B) is a function of the magnetic field strength B. The dependence of (B) on B is shown in the figure.
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields?
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields? Electrical resistance of certain materials, known as superconductors, changes abruptly from a nonzero value to zero as their temperature is lowered below a critical temperature (0). An interesting property of superconductors is that their critical temperature becomes smaller than (0) if they are placed in a magnetic field, i.e., the critical temperature (B) is a function of the magnetic field strength B. The dependence of (B) on B is shown in the figure.
In the graphs below, the resistance R of a superconductor is shown as a function of its temperature T for two different magnetic fields (sold line) and (dashed line). If is larger than , which of the following graphs shows the correct variation of R with T in these fields?
physics-General
physics-
A thin flexible wire of length L is connected to two adjacent fixed points and carries a current I in the clockwise direction, as shown in the figure. When the system is put in a uniform magnetic field of strength B going into the plane of the paper, the wire takes the shape of a circle. The tension in the wire is :
A thin flexible wire of length L is connected to two adjacent fixed points and carries a current I in the clockwise direction, as shown in the figure. When the system is put in a uniform magnetic field of strength B going into the plane of the paper, the wire takes the shape of a circle. The tension in the wire is :
physics-General
physics-
A magnetic field 
exists in the region 
and 
in the region 
, where 
is a positive constant. A positive point charge moving with a velocity 
where 
is a positive constant, enters the magnetic field at x = a. The trajectory of the charge in this region can be like
A magnetic field exists in the region and in the region , where is a positive constant. A positive point charge moving with a velocity where is a positive constant, enters the magnetic field at x = a. The trajectory of the charge in this region can be like
physics-General
physics-
An electron moving with a speed u along the positive x–axis at y = 0 enters a region of uniform magnetic field 
which exists to the right of y–axis. The electron exist from the region after some time with the speed v at co–ordinate y, then :
An electron moving with a speed u along the positive x–axis at y = 0 enters a region of uniform magnetic field which exists to the right of y–axis. The electron exist from the region after some time with the speed v at co–ordinate y, then :
physics-General
physics-
A current carrying loop is placed in a uniform magnetic field in four different orientations, I, II, III, IV, arrange them in the decreasing order of potential energy
A current carrying loop is placed in a uniform magnetic field in four different orientations, I, II, III, IV, arrange them in the decreasing order of potential energy
physics-General
physics-
A conducting loop carrying a current I is placed in a uniform magnetic field pointing into the plane of the paper as shown. The loop will have a tendency to
A conducting loop carrying a current I is placed in a uniform magnetic field pointing into the plane of the paper as shown. The loop will have a tendency to
physics-General
