Balbharati solutions for Physics [English] 12 Standard HSC Maharashtra State Board chapter 10 - Magnetic Fields due to Electric Current [Latest edition]

A conductor has 3 segments; two straight and of length L each and a semicircular with radius R. It carries a current I. What is the magnetic field B at point P?

Choose the correct option:

Figures (a) and (b) show two Amperean loops associated with the conductors carrying current I in the sense shown. The `oint vecB * vecdl` in the cases (a) and (b) are, respectively.

A proton enters a perpendicular uniform magnetic field B at origin along the positive x axis with a velocity v as shown in the figure. Then it will follow the following path. [The magnetic field is directed into the paper].

Choose the correct option.

A conducting thick copper rod of length 1 m carries a current of 15A and is located on the Earth's equator. There the magnetic flux lines of Earth's magnetic field are horizontal, with the field of 1.3 x 10^-4T, south to north. The magnitude and direction of the force on the rod, when it is oriented so that current flows from west to east are ______.

A charged particle is in motion having initial velocity `vecv` when it enters into a region of uniform magnetic field perpendicular to `vecv`. Because of the magnetic force the kinetic energy of the particle will ______.

A piece of straight wire has mass 20 g and length 1 m. It is to be levitated using a current of 1 A flowing through it and a perpendicular magnetic field B in a horizontal direction. What must be the magnitude B of the magnetic field?

Calculate the value of the magnetic field at a distance of 2 cm from a very long straight wire carrying a current of 5 A (Given: μ₀ = 4π × 10^-7 Wb/Am).

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]

An alpha particle (the nucleus of helium atom) (with charge +2e) is accelerated and moves in a vacuum tube with kinetic energy = 10.00 MeV. On applying a transverse a uniform magnetic field of 1.851 T, it follows a circular trajectory of radius 24.60 cm. Obtain the mass of the alpha particle.

[charge of electron = 1.62 × 10^-19 C]

Two wires shown in the figure are connected in a series circuit and the same current of 10 A passes through both, but in opposite directions. The separation between the two wires is 8 mm. The length AB is 22 cm. Obtain the direction and magnitude of the magnetic field due to current in wire 2 on the following figure segment AB of wire 1. Also, obtain the magnitude and direction of the force on wire 1. [μ₀ = 4π × 10^-7 T.m/A]

A very long straight wire carries a current of 5.2 A. What is the magnitude of the magnetic field at a distance 3.1 cm from the wire?

Currents of equal magnitude pass through two long parallel wires having a separation of 1.35 cm. If the force per unit length on each of the wires is 4.76 x 10^-2 N, what must be I ?

The magnetic field at a distance of 2.4 cm from a long straight [current-carrying] wire is 16 µT. What is the current through the wire?

The magnetic field at the centre of a circular current carrying loop of radius 12.3 cm is 6.4 × 10^-6 T. What is the magnetic moment of the loop?

A circular loop of radius 9.7 cm carries a current 2.3 A. Obtain the magnitude of the magnetic field
(a) at the centre of the loop
(b) at a distance of 9.7 cm from the centre of the loop but on the axis.

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?

For proton acceleration, a cyclotron is used in which a magnetic field of 1.4 Wb/m² is applied. Find the time period for reversing the electric field between the two Ds.

A moving coil galvanometer has been fitted with a rectangular coil having 50 turns and dimensions 5 cm × 3 cm. The radial magnetic field in which the coil is suspended is of 0.05 Wb/m². The torsional constant of the spring is 1.5 × 10⁻⁹ Nm/degree. Obtain the current required to be passed through the galvanometer so as to produce a deflection of 30°.

A solenoid of length π m and 5 cm in diameter has winding of 1000 turns and carries a current of 5 A. Calculate the magnetic field at its center along the axis.

A toroid of a central radius of 10 cm has windings of 1000 turns. For a magnetic field of 5 × 10^-2 T along its central axis, what current is required to be passed through its windings?

In a cyclotron, protons are to be accelerated. The radius of its D is 60 cm. and its oscillator frequency is 10 MHz. What will be the kinetic energy of the proton thus accelerated?
(Proton mass = 1.67 × 10⁻²⁷ kg, e = 1.60 × 10⁻¹⁹ C, eV = 1.6 × 10⁻¹⁹ J)

A wire loop of the form shown in the following figure carries a current I. Obtain the magnitude and direction of the magnetic field at P. (Given: `B = (mu_0I)/(4pir) sqrt2` due to

Two long parallel wires, both carrying current I directed into the plane of the page, are separated by a distance R. Show that at a point P equidistant from the wires and subtending an angle θ from the plane containing the wires, the magnitude of the magnetic field is B = `(mu_0)/pi "I"/"R"` sin 2θ. What is the direction of the magnetic field?

The figure shows a cylindrical wire of diameter a, carrying a current I. The current density in the wire is in the direction of the axis and varies linearly with radial distance r from the axis according to the relation J = `"J"_0 "r"/"a"`. Obtain a magnetic field B inside the wire at a distance r from its center.

In the problem, what will be the magnetic field B inside the wire at a distance r from its center, if the current density J is uniform across the cross-section of the wire? Figure shows a section of a very long cylindrical wire of diameter a, carrying a current I. The current density which is in the direction of the central axis of the wire varies linearly with radial distance r from the axis according to the relation J = J_o r/a.