Q. 195.0( 2 Votes )
A rigid wire consists of a semicircular portion of radius R and two straight sections figure. The wire is partially immersed in a perpendicular magnetic field B as shown in the figure. Find the magnetic force on the wire if it carries a current i.

Answer :
Given-
Radius of the semi-circular portion = R
Perpendicular Magnetic field = B
Electric current flowing through the wire = I A
Given in the question, the wire is partially immersed in a perpendicular magnetic field.
As AB and CD are straight wires of length l each and strength of the magnetic field is also same on both the wires, the force acting on these wires will be equal in magnitude
Direction of force can be found out using Fleming’s left hand rule.
So, their directions will be opposite to each other.
So, the magnetic force on the wire AB and the force on the wire CD are equal and opposite to each other. Both the forces cancel out each other.
Therefore, only the semicircular loop RC will experience a net magnetic force.
Here, angle between the length of the wire and magnetic field, θ = 900
We know ,magnetic force acting on a current carrying wire in an uniform magnetic field is given by
where,
B= magnetic field
I = current
l = length of the wire
and θ = the angle between B and l
Here, length l = 2R
Rate this question :






















A rectangular coil of 100 turns has length 5 cm and width 4 cm. It is placed with its plane parallel to a uniform magnetic field and a current of 2A is sent through the coil. Find the magnitude of the magnetic field B, if the torque acting on the coil is 0.2 N m–1.
HC Verma - Concepts of Physics Part 2A circular coil of radius 2.0 cm ahs 500 turns in it and carries a current of 1.0 A. Its axis makes an angle of 30° with the uniform magnetic field of magnitude 0.40 T that exist in the space. Find the torque acting on the coil.
HC Verma - Concepts of Physics Part 2A rectangular loop of sides 20 cm and 10 cm carries a current of 5.0 A. A uniform magnetic field of magnitude 0.20 T exists parallel to the longer side of the loop.
(a) What is the force acting on the loop?
(b) What is the torque acting on the loop?
HC Verma - Concepts of Physics Part 2
A circular loop carrying a current i has wire of total length L. A uniform magnetic field B exists parallel to the plane of the loop.
(a) Find the torque on the loop.
(b) If the same length of the wire is used to form a square loop, what would be the torque? Which is larger?
HC Verma - Concepts of Physics Part 2
Fe+ions are acceleration through a potential difference of 500 V and are injected normally into a homogeneous magnetic field B of strength 20.0 mT. Find the radius of the circular paths followed by the isotopes with mass numbers 57 and 58. Take the mass of an ion = A(1.6 × 10–27) kg where A is the mass number.
HC Verma - Concepts of Physics Part 2A charged particle moves along a circle under the action of possible constant electric and magnetic fields. Which of the following are possible?
HC Verma - Concepts of Physics Part 2A charged particle moves in a gravity-free space without change in velocity. Which of the following is/are possible?
HC Verma - Concepts of Physics Part 2If a charged particle at rest experiences no electromagnetic force,
HC Verma - Concepts of Physics Part 2If a charged particle goes unaccelerated in a region containing electric and magnetic fields.
HC Verma - Concepts of Physics Part 2