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प्रश्न
According to the right-hand rule, the direction of magnetic induction if the current is directed in an anticlockwise direction is ______
विकल्प
perpendicular and inwards
perpendicular and outwards
same as current
opposite to that of current
उत्तर
According to the right-hand rule, the direction of magnetic induction if the current is directed in an anticlockwise direction is perpendicular and outwards.
संबंधित प्रश्न
Seema’s uncle was advised by his doctor to have an MRI (Magnetic Resonance Imaging) scan of his brain. Her uncle felt it to be expensive and wanted to postpone it. When Seema learnt about this, she took the help of her family and also approached the doctor, who also offered a substantial discount. She then convinced her uncle to undergo the test to enable the doctor to know the condition of his brain. The information thus obtained greatly helped the doctor to treat him properly.
Based on the above paragraph, answer the following questions:
(a) What according to you are the values displayed by Seema, her family and the doctor?
(b) What could be the possible reason for MRI test to be so expensive?
(c) Assuming that MRI test was performed using a magnetic field of 0.1 T, find the minimum and maximum values of the force that the magnetic field could exert on a proton (charge = 1.6 x 10-19 C) moving with a speed of 104 m/s.
Deduce the expression for the magnetic field at a point on the axis of a current carrying circular loop of radius ‘R’ distant ‘x’ from the centre. Hence, write the magnetic field at the centre of a loop.
A conducting loop is held above a current carrying wire PQ as shown in the figure. Depict the direction of the current induced in the loop when the current in the wire PQ is constantly increasing.
The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.
A rod of length l is moved horizontally with a uniform velocity 'v' in a direction perpendicular to its length through a region in which a uniform magnetic field is acting vertically downward. Derive the expression for the emf induced across the ends of the rod.
A circular coil of wire consisting of 100 turns, each of radius 8.0 cm carries a current of 0.40 A. What is the magnitude of the magnetic field B at the centre of the coil?
A circular coil carrying a current I has radius R and number of turns N. If all the three, i.e. the current
I, radius R and number of turns N are doubled, then, the magnetic field at its centre becomes:
(a) Double
(b) Half
(c) Four times
(d) One fourth
Obtain an expression for magnetic flux density B at the centre of a circular coil of radius R, having N turns and carrying a current I
A circular coil of N turns and radius R carries a current I. It is unwound and rewound to make another coil of radius R/2, current I remaining the same. Calculate the ratio of the magnetic moments of the new coil and original coil.
A straight horizontal wire of mass 10 mg and length 1.0 m carries a current of 2.0 A. What minimum magnetic field B should be applied in the region, so that the magnetic force on the wire may balance its weight?
Write the expression for the Lorentz force F in vector form.
Choose the correct alternative and rewrite the following:
What will happen to the current passing through a resistance, if the potential difference across it is doubled and the resistance is halved?
An electron is moving with a speed of 3.2 × 107 m/s in a magnetic field of 6.00 × 10-4 T perpendicular to its path. What will be the radium of the path? What will be frequency and the energy in keV?
[Given: mass of electron = 9.1 × 10−31 kg, charge e = 1.6 × 10−19 C, 1 eV = 1.6 × 10−19 J]
A conductor has three segments; two straights of length L and a semicircular with radius R. It carries a current I What is the magnetic field B at point P?
Explain "Magnetic force never does any work on moving charges".
Show that currents in two long, straight, parallel wires exert forces on each other. Derive the expression for the force per unit length on each conductor.
A very high magnetic field is applied to a stationary charge. Then the charge experiences ______.
For a circular coil of radius R and N turns carrying current I, the magnitude of the magnetic field at a point on its axis at a distance x from its centre is given by,
B = `(μ_0"IR"^2"N")/(2("x"^2 + "R"^2)^(3/2))`
(a) Show that this reduces to the familiar result for field at the centre of the coil.
(b) Consider two parallel co-axial circular coils of equal radius R, and number of turns N, carrying equal currents in the same direction, and separated by a distance R. Show that the field on the axis around the mid-point between the coils is uniform over a distance that is small as compared to R, and is given by, B = `0.72 (μ_0"NI")/"R"` approximately.
[Such an arrangement to produce a nearly uniform magnetic field over a small region is known as Helmholtz coils.]
An electron travelling west to east enters a chamber having a uniform electrostatic field in north to south direction. Specify the direction in which a uniform magnetic field should be set up to prevent the electron from deflecting from its straight line path.
An electron emitted by a heated cathode and accelerated through a potential difference of 2.0 kV, enters a region with uniform magnetic field of 0.15 T. Determine the trajectory of the electron if the field (a) is transverse to its initial velocity, (b) makes an angle of 30° with the initial velocity.
A deuteron of kinetic energy 50 keV is describing a circular orbit of radius 0.5 metre in a plane perpendicular to the magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5 metre in the same plane with the same B is ______.
An infinitely long straight conductor carries a current of 5 A as shown. An electron is moving with a speed of 105 m/s parallel to the conductor. The perpendicular distance between the electron and the conductor is 20 cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant.
Consider a wire carrying a steady current, I placed in a uniform magnetic field B perpendicular to its length. Consider the charges inside the wire. It is known that magnetic forces do no work. This implies that ______.
- motion of charges inside the conductor is unaffected by B since they do not absorb energy.
- some charges inside the wire move to the surface as a result of B.
- if the wire moves under the influence of B, no work is done by the force.
- if the wire moves under the influence of B, no work is done by the magnetic force on the ions, assumed fixed within the wire.
A cubical region of space is filled with some uniform electric and magnetic fields. An electron enters the cube across one of its faces with velocity v and a positron enters via opposite face with velocity – v. At this instant ______.
- the electric forces on both the particles cause identical accelerations.
- the magnetic forces on both the particles cause equal accelerations.
- both particles gain or loose energy at the same rate.
- the motion of the centre of mass (CM) is determined by B alone.
A beam of light travelling along X-axis is described by the electric field Ey = 900 sin ω(t - x/c). The ratio of electric force to magnetic force on a charge q moving along Y-axis with a speed of 3 × 107 ms-1 will be : [Given speed of light = 3 × 108 ms-1]
Write the expression for the Lorentz force on a particle of charge q moving with a velocity `vecv` in a magnetic field `vecB`. When is the magnitude of this force maximum? Show that no work is done by this force on the particle during its motion from point `vecr_1` to point `vecr_2`.
Distinguish between the forces experienced by a moving charge in a uniform electric field and in a uniform magnetic field. (Any two points)
State dimensions of magnetic field.
