Physics
posted by Jake
1.
A rectangular coil 0.065 m by 0.080 m is positioned
so that its crosssectional area is perpendicular
to the direction of a magnetic field.
The coil has 66 turns and a total resistance of
7.6 Ω and the field decreases at a rate of 2.5
T/s.
What is the magnitude of the induced current
in the coil?
Answer in units of A.
2.
A student attempts to make a simple generator by passing a single loop of wire between the poles of a horseshoe magnet with a magnetic field of 2.0 ×10−2 T. The area of the loop is 4.87 ×10−3 m2 and is moved perpendicular to the magnetic field lines.
In what time interval will the student have
to move the loop out of the magnetic field in
order to induce an EMF of 1.9 V?
Answer in units of s.
3.
A student attempts to make a simple generator
by wrapping a long piece of wire across
a cylinder with a crosssectional area of 1.076×10−3 m2. She then passes the coil betweenthe poles of a horseshoe magnet with a magnetic field of 2.2 ×10−2 T. The student finds that by removing the coil perpendicular to the magnetic field lines during 0.29 s, a voltage drop of 145 mV can be induced across the wire.
How many turns of wire are wrapped
around the coil?
4.
A bolt of lightning, such as the one shown on
the left in the figure, behaves like a vertical
wire conducting electric current. As a result,
it produces a magnetic field whose strength
varies with the distance from the lightning. A
139turn circular coil with a radius of 0.842
m is oriented perpendicular to the magnetic
field as shown. The magnetic field at the coil
drops from 4.99×10−3 T to 0.00 T in 10.7 µs.
What is the average emf induced in the
coil?
Answer in units of V.

bobpursley
a. EMF=N*area*dB/dt
then current= EMF/resistance
b. EMF= above, solve or dt.
Respond to this Question
Similar Questions

Physics
An electric generator contains a coil of 100 turns of wire, each turn forming a rectangular loop 50cm by 30cm. The coil is placed entirely in a uniform magnetic field with magnitude, B = 3.5T and direction initially perpendicular to … 
Physics
A rectangular coil of 70 turns, dimensions 0.100 m by 0.200 m and total resistance 10.0 ohms, rotates with angular speed 32.0 rad/s about the y axis in a region where a 1.00 T magnetic field is directed along the x axis. The rotation … 
Physics
A flat circular coil with 192 turns, a radius of 2.35 x 102 m, and a resistance of 0.359 Ù is exposed to an external magnetic field that is directed perpendicular to the plane of the coil. The magnitude of the external magnetic field … 
Physics
A coil with 347 turns of wire, a total resistance of 49 Ω, and a crosssectional area of 0.28 m2 is positioned with its plane perpendicular to the ﬁeld of a powerful electromagnet. What average current is induced in the … 
physics
A circular coil with a radius of 25 cm has 20 turns. The coil is oriented perpendicularly to a magnetic field whose initial magnitude is 3.2 T. Suddenly, the magnetic field vanishes in 0.4 s. a. What is the initial magnetic flux in … 
Physics
A coil is wrapped with 200 turns of wire on the perimeter of a square frame of sides 20.5 cm. Each turn has the same area, equal to that of the frame, and the total resistance of the coil is 2.01 Ω. A uniform magnetic field is … 
Physics
A circular coil (660 turns, radius = 0.037 m) is rotating in a uniform magnetic field. At t = 0 s, the normal to the coil is perpendicular to the magnetic field. At t = 0.024 s, the normal makes an angle of 45o with the field because … 
Physics HELP
A coil with 337 turns of wire, a total resistance of 47 Ω, and a crosssectional area of 0.35 m2 is positioned with its plane perpendicular to the field of a powerful electromagnet. What average current is induced in the coil during … 
Physics HELP
A rectangular coil 0.065 m by 0.080 m is positioned so that its crosssectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate of … 
Physics HELP
1. A rectangular coil 0.065 m by 0.080 m is positioned so that its crosssectional area is perpendicular to the direction of a magnetic field. The coil has 66 turns and a total resistance of 7.6 Ω and the field decreases at a rate …