Chapter 4 Moving Charges and Magnetism
Top questions
See all →- 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
- A charged particle enters an environment of a strong and non-uniform magnetic field varying from point A space-fixed magnetic field cannot do work on moving charge and hence the speed remains the same (so also KE). 1
- A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) The force on a charged particle moving in a magnetic field is F = q( v x B ) = qvB sin θ. If θ = 0° or 180°, force is zero and the particle... 1
- In Exercise. 11 obtain the frequency of revolution of the electron in its circular orbit Frequency in Exercise 11, υ = qB / 2πm = frac1.6 × 10⁻¹⁹ × 6.5 × 10⁻⁴2 × π × 9.1 × 10⁻³¹ = 18 MHz 2