13.7 Applications of electromagnetic induction  (Page 2/4)

Shown in the following figure is a long, straight wire and a single-turn rectangular loop, both of which lie in the plane of the page. The wire is parallel to the long sides of the loop and is 0.50 m away from the closer side. At an instant when the emf induced in the loop is 2.0 V, what is the time rate of change of the current in the wire?

A metal bar of mass 500 g slides outward at a constant speed of 1.5 cm/s over two parallel rails separated by a distance of 30 cm which are part of a U-shaped conductor. There is a uniform magnetic field of magnitude 2 T pointing out of the page over the entire area. The railings and metal bar have an equivalent resistance of $150\text{Ω.}$ (a) Determine the induced current, both magnitude and direction. (b) Find the direction of the induced current if the magnetic field is pointing into the page. (c) Find the direction of the induced current if the magnetic field is pointed into the page and the bar moves inwards.

A current is induced in a circular loop of radius 1.5 cm between two poles of a horseshoe electromagnet when the current in the electromagnet is varied. The magnetic field in the area of the loop is perpendicular to the area and has a uniform magnitude. If the rate of change of magnetic field is 10 T/s, find the magnitude and direction of the induced current if resistance of the loop is $25\text{Ω}$ .

A metal bar of length 25 cm is placed perpendicular to a uniform magnetic field of strength 3 T. (a) Determine the induced emf between the ends of the rod when it is not moving. (b) Determine the emf when the rod is moving perpendicular to its length and magnetic field with a speed of 50 cm/s.

A coil with 50 turns and area 10 ${\text{cm}}^2$ is oriented with its plane perpendicular to a 0.75-T magnetic field. If the coil is flipped over (rotated through $180\text{°}$ ) in 0.20 s, what is the average emf induced in it?

A 2-turn planer loop of flexible wire is placed inside a long solenoid of n turns per meter that carries a constant current $I_0$ . The area A of the loop is changed by pulling on its sides while ensuring that the plane of the loop always remains perpendicular to the axis of the solenoid. If $n=500\text{turns}$ per meter, $I_0=20\text{A,}$ and $A=20{\text{cm}}^2,$ what is the emf induced in the loop when $dA\text{/}dt=100\text{?}$