Download tutorial 1 - Portal UniMAP

DKT113 Engineering Physics
Semester 1 Session 2010/11
TUTORIAL 7
1. a)
Define poles-force law or law of poles
b)
State the function of Right Hand Rules Law
c)
Sketch the magnetic field lines for the poles as shown in Figure below.
i)
N
N
ii)
S
ii
N
iii)
S
S
2. An electron travels at a speed of 2.0  104 m s through a uniform magnetic field
whose magnitude is 1.2 103 T. What is the magnitude of the magnetic force on the
electron if its velocity and the magnetic field
(a) are perpendicular,
(b) make an angle of 45°
(c) are parallel
3.
A 2.0-m length of straight wire carries a current of 20 A in a uniform magnetic field of 50
mT whose direction is at an angle of 37° from the direction of the current. Find the force
on the wire.
4.
A straight wire 50 cm long conducts a current of 4.0 A directed vertically upward. If the
wire is acted on by a force of 1.0  102 N in the eastward direction due to a magnetic
field at right angles to the length of the wire, what are the magnitude and direction of
the magnetic field?
5.
A horizontal magnetic field of 1.0  10 4 T is at an angle of 30° to the direction of the
current in a straight, horizontal wire 75 cm long. If the wire carries a current of 15 A,
what is the magnitude of the force on the wire?
6.
A charge of 0.050 C moves vertically in a field of 0.080 T that is oriented 45° from the
vertical. What speed must the charge have such that the force acting on it is 10 N?
7.
The magnetic field at the center of a 50-turn coil of radius 15 cm is 0.80 mT. Find the
current in the coil.
8.
A long, straight wire carries a current of 2.5 A. Find the magnitude of the magnetic field
25 cm from the wire.
9.
In a physics lab, a student discovers that the magnitude of the magnetic field at a certain
distance from a long wire is 4.0 T. If the wire carries a current of 5.0 A, what is the
distance of the magnetic field from the wire?