Physics-
General
Easy
Question
An infinitely long conductor PQR is bent to form a right angle as shown in figure. A current I flows through PQR. The magnetic field due to this current at the point M is 
. Now, another infinitely long straight conductor QS is connected at Q, so that current is I/2 in QR as well as in QS, the current in PQ remaining unchanged. The magnetic field at M is now 
. The ratio / is given by :
- 1/2
- 1
- 2/3
- 2
The correct answer is: 2/3
Related Questions to study
physics-
Hysteresis loops for two magnetic materials A and B are given below :
These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use:
Hysteresis loops for two magnetic materials A and B are given below :
These materials are used to make magnets for electric generators, transformer core and electromagnet core. Then it is proper to use:
physics-General
physics-
Two long current carrying thin wires, both with current I, are held by insulating threads of length L and are in equilibrium as shown in the figure, with threads making an angle 
with the vertical. If wires have mass 
per unit length then the value of I is : (g = gravitational acceleration)
Two long current carrying thin wires, both with current I, are held by insulating threads of length L and are in equilibrium as shown in the figure, with threads making an angle with the vertical. If wires have mass per unit length then the value of I is : (g = gravitational acceleration)
physics-General
physics-
A rectangular loop of sides 10 cm and 5 cm carrying a current I of 12 A is placed in different orientations as shown in the figures below ;
If there is a uniform magnetic field of 0.3 T in the positive z direction, in which orientations the loop would be in (i) stable equilibrium and (ii) unstable equilibrium ?
A rectangular loop of sides 10 cm and 5 cm carrying a current I of 12 A is placed in different orientations as shown in the figures below ;
If there is a uniform magnetic field of 0.3 T in the positive z direction, in which orientations the loop would be in (i) stable equilibrium and (ii) unstable equilibrium ?
physics-General
physics-
A conductor lies along the z-axis at 
m and carries a fixed current of 10.0 A in 
direction (see figure). For a field 
T, find the power required to move the conductor at constant speed to x = 2.0 m, y = 0 m in 
s. Assume parallel motion along the x-axis
A conductor lies along the z-axis at m and carries a fixed current of 10.0 A in direction (see figure). For a field T, find the power required to move the conductor at constant speed to x = 2.0 m, y = 0 m in s. Assume parallel motion along the x-axis
physics-General
physics-
A current loop ABCD is held fixed on the plane of the paper as shown in the figure. The arcs BC (radius = b) and DA (radius = a) of the loop are joined by two straight wires AB and CD. A steady current I is flowing in the loop. Angle made by AB and CD at the origin O is 
. Another straight thin wire with steady current I1 flowing out of the plane of the paper is kept at the origin
The magnitude of the magnetic field (B) due to the loop ABCD at the origin (O) is :-
A current loop ABCD is held fixed on the plane of the paper as shown in the figure. The arcs BC (radius = b) and DA (radius = a) of the loop are joined by two straight wires AB and CD. A steady current I is flowing in the loop. Angle made by AB and CD at the origin O is . Another straight thin wire with steady current I1 flowing out of the plane of the paper is kept at the origin
The magnitude of the magnetic field (B) due to the loop ABCD at the origin (O) is :-
physics-General
physics-
Wires 1 and 2 carrying currents 
and 
respectively are inclined at an angle 
to each other. What is the force on a small element 
of wire 2 at a distance r from wire 1(as shown in figure) due to the magnetic field of wire 1 ?
Wires 1 and 2 carrying currents and respectively are inclined at an angle to each other. What is the force on a small element of wire 2 at a distance r from wire 1(as shown in figure) due to the magnetic field of wire 1 ?
physics-General
physics-
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, 
. Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship 
where q is the charge of the particle and 
is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship 
where q is the charge of the particle, 
is the speed of the particle, and 
is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Particles of identical mass and charge are sent through the filter at varying speeds, and the magnitude of acceleration of each particle is recorded as it first begins to be deflected. If the filter is set to detect particles of speed , which one of the following is correct graph between acceleration and velocity of particle:
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Particles of identical mass and charge are sent through the filter at varying speeds, and the magnitude of acceleration of each particle is recorded as it first begins to be deflected. If the filter is set to detect particles of speed , which one of the following is correct graph between acceleration and velocity of particle:
physics-General
physics-
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Which of the following statements is true regarding a charged particle that is moving through the filter at a speed that is less than the filter speed ?
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Which of the following statements is true regarding a charged particle that is moving through the filter at a speed that is less than the filter speed ?
physics-General
chemistry-
Two oxides of Metal contain 27.6% and 30% oxygen respectively. If the formula of first oxide is 
then formula of second oxide is -
Two oxides of Metal contain 27.6% and 30% oxygen respectively. If the formula of first oxide is then formula of second oxide is -
chemistry-General
physics-
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Which of the following is true about the velocity filter shown in figure?
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
Which of the following is true about the velocity filter shown in figure?
physics-General
physics-
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
The electric and magnetic fields in the filter of figure are adjusted to detect particles with positive charge q of a certain speed, . Which of the following expressions is equal to this speed ?
A velocity filter uses the properties of electric and magnetic fields to select charged particles that are moving with a specific velocity. Charged particles with varying speeds are directed into the filter as shown in figure. The filter consists of an electric field E and a magnetic field B, each of constant magnitude, directed perpendicular to each other as shown. The particles that move straight through the filter with their direction unaltered by the fields have the specific filter speed, . Those with speeds to may experience sufficiently little deflection that they also enter the detector.
The charged particle will experience a force due to the electric field given by the relationship where q is the charge of the particle and is the electric field. The moving particle will also experience a force due to the magnetic field. This force acts to oppose the force due to the electric field. The strength of the force due to the magnetic field is given by the relationship where q is the charge of the particle, is the speed of the particle, and is the magnetic field strength. When the forces due to the two fields are equal and opposite, the net force on the particle will be zero, and the particle will pass through the filter with its path unaltered. The electric and magnetic field strengths can be adjusted to choose the specific velocity to be filtered. The effects of gravity can be neglected.
The electric and magnetic fields in the filter of figure are adjusted to detect particles with positive charge q of a certain speed, . Which of the following expressions is equal to this speed ?
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
The current density in wire a is
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
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 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
