Doubtly
@Doubtly · Joined Feb 2021
- Answers
- 3,792
- Questions
- 4,033
- Upvotes received
- 424
- In the above problem, what will be the magnetic field B inside the wire at a distance r from its axis Figure shows the cross section of a long straight wire of radius a that carries a current I out of the page. Because the current is uniforml... 1
- Distinguish between the forces experienced by a moving charge in a uniform electric field A charge q moving with a velocity v through a magnetic field of induction B experiences a magnetic force perpendicular both to B and v . Exp... 1
- What is special about a radial magnetic field ? Why is it useful in a moving coil galvanometer ? Advantage of radial magnetic field in a moving- coil galvanometer: As the coil rotates, its plane is always parallel to the field. That way,... 1
- State Ampere’s law. Explain how is it useful in different situations. Ampere's circuital law : In free space, the line integral of magnetic induction around a closed path in a magnetic field is equal to p0 time... 1
- Currents in two infinitely long, parallel wires exert forces on each other. Is this consistent with Newton’s third law? Yes, they are equal in magnitude and opposite in direction and act on the contrary parts : F _(on 2 by 1) = F _(on 1 by 2). Thus, they form... 1
- What is the fundamental difference between an electric dipole and a magnetic dipole? If a magnet is carefully and repeatedly cut, it would expose two new faces with opposite poles such that each piece would still be a magnet.... 1
- What is an ideal solenoid? A solenoid is a long wire wound in the form of a helix. An ideal solenoid is tightly wound and infinitely long, i.e., its turns are closely... 1
- Choosing different Amperean loops, show that out-side an ideal toroid B = 0. From below figure, the inner Amperean loop does not enclose any current while the outer Amperean loop encloses equal number of I_in and I_ou... 1
- What is an ideal toroid? A toroid is a toroidal solenoid. An ideal toroid consists of a long conducting wire wound tightly around a torus, a doughnut-shaped ring, ma... 1
- Explain Magnetic Dipole Moment A current-carrying coil reacts to an external magnetic field in the same way a magnetic dipole does (or a bar magnet). Like a magnetic dipol... 1
- Advantage of radial magnetic field in a moving-coil galvanometer As the coil rotates, its plane is always parallel to the field. That way, the deflecting torque is always a maximum depending only on the cur... 1
- What will happen if the magnetic field in a moving-coil galvanometer is not radial? Suppose the magnetic field is uniform but not radial. Then, when the coil comes to rest after rotation through an angle θ, NIAB cos θ = Kθ (i... 1
- State under what conditions will a charged particle moving through a uniform magnetic field travel in (i) A charged particle travels undeviated through a magnetic field B if its velocity v is parallel or antiparallel to . In this case, the mag... 1
- Explain why the magnetic force on a charged particle cannot change the linear speed and the kinetic energy The magnetic force on a particle carrying a charge q and moving with a velocity v in a magnetic field of induction B is F_m = q v×B . At ever... 1
- Expression for the Lorentz force on a charge due to an electric field as well as a magnetic field A charge q moving with a velocity through a magnetic field of induction B experiences a magnetic force perpendicular both to B and . v Experi... 1
- When current is passed through the conductor, the compass needle deflects. Why? The compass needle is now subjected to the earth’s magnetic field and the magnetic field of the straight conductor. 1
- The wires which connect the battery of an automobile to its starting motor carry a current of 300 A (for a short time). I = 300 A, l = 70 cm, r = 1.5 cm F = fracμ₀ I₁ I₂2 π r = frac4 π × 10⁻⁵ × 300 × 3002 × 1.5 × 10⁻² = 1.2 N The force is repulsive. 1
- An electron travelling west to east enters a chamber having a uniform electrostatic field The force on the electron due to the electric field is south to north. To oppose this the force due to the magnetic field should be to the s... 1