Magnetic Fields - exam practice
Magnetic Fields
Question 1 of 10
1 of 10
The diagram shows a clockwise current I in a circular coil placed in a uniform magnetic field B with the plane of the coil perpendicular to the magnetic field.
What is the effect on the coil of the interaction between the current and the magnetic field?
Question 2 of 10
2 of 10
Charged particles, each of mass m and charge Q, travel at a constant speed in a circle of radius r in a uniform magnetic field of flux density B.
Which expression gives the frequency of rotation of a particle in the beam?
Question 3 of 10
3 of 10
When an electron is moving at a speed v perpendicular to a uniform magnetic field of flux density B, it follows a path of radius R.
A second electron moves at a speed perpendicular to a uniform magnetic field of flux density 4B.
What is the radius of the path of the second electron?
Question 4 of 10
4 of 10
Different magnetic fields are present in the two chambers shown. A particle enters the first chamber at a velocity of
80 m s–1 and is deflected into a circular path of radius 200 mm. In the second chamber it follows a circular path of radius 100 mm.
The particle leaves the second chamber at a speed of
Question 5 of 10
5 of 10
A charged particle moves in a circular path of radius 1.2cm in a uniform magnetic field.
The direction of the magnetic field is perpendicular to the plane of the paper.
The particle has mass m, charge +Q and speed v.
Another particle of mass 3m, charge +2Q and speed v moves in a circular path of radius R in the same magnetic field.
What is the value of R?
Question 6 of 10
6 of 10
An electron moves in a circle of radius 2.0 cm in a uniform magnetic field of flux density 170 mT.
What is the momentum of this electron?
Question 7 of 10
7 of 10
A beam of charged particles is not deflected when it passes through a region where both electric and magnetic fields are present.
Which statement is notcorrect?
Question 8 of 10
8 of 10
A horizontal straight wire of length 0.30 m carries a current of 2.0 A perpendicular to a horizontal uniform magnetic field of flux density 5.0 × 10−2 T. The wire ‘floats’ in equilibrium in the field.
What is the mass of the wire?
Question 9 of 10
9 of 10
A horizontal wire of length 0.50 m and weight 1.0 N is placed in a uniform horizontal magnetic field of flux density 1.5 T directed at 90° to the wire.
What is the current that just supports the wire?
Question 10 of 10
10 of 10
The graph shows how the flux linkage, NФ, through a coil changes when the coil is moved into a magnetic field.
The emf induced in the coil