Exam 22: Electromagnetic Induction

Two coils,1 and 2,with iron cores are positioned as shown in the figure.Coil 1 is part of a circuit with a battery and a switch. -Immediately after the switch S is closed,which one of the following statements is true?

A single conducting loop with an area of 2.0 m² rotates in a uniform magnetic field so that the induced emf has a sinusoidal time dependence as shown. -Determine the strength of the magnetic field in which the loop rotates.

Which one of the following statements concerning transformers is false?

The figure shows a uniform,3.0-T magnetic field that is normal to the plane of a conducting,circular loop with a resistance of 1.5 and a radius of 0.024 m.The magnetic field is directed out of the paper as shown.Note: The area of the non-circular portion of the wire is considered negligible compared to that of the circular loop. -What is the magnitude of the average induced emf in the loop if the magnitude of the magnetic field is doubled in 0.4 s?

The Earth's magnetic field passes through a square tabletop with a magnitude of 4.95 × 10^-⁵ T and is directed at an angle of 165° relative to the normal of the tabletop.If the tabletop has 1.50-m sides,what is the magnitude of the magnetic flux through it?

A loop is pulled with a force F to the right to maintain a constant speed of 8.0 m/s.The loop has a length of 0.15 m,a width of 0.080 m,and a resistance of 200.0 .At the instant shown,the loop is partially in and partially out of a uniform magnetic field that is directed into the paper.The magnitude of the field is 1.2 T. -What is the induced current in the loop?

A small power plant produces a voltage of 6.0 kV and 150 A.The voltage is stepped up to 240 kV by a transformer before it is transmitted to a substation.The resistance of the transmission line between the power plant and the substation is 75 . -What percentage of the power produced at the power plant is lost in transmission to the substation?

Two coils share a common axis as shown in the figure.The mutual inductance of this pair of coils is 6.0 mH.If the current in coil 1 is changing at the rate of 3.5 A/s,what is the magnitude of the emf generated in coil 2?

A circuit is pulled with a 21-N force toward the right to maintain a constant speed v.At the instant shown,the loop is partially in and partially out of a uniform magnetic field that is directed into the paper.As the circuit moves,a 4.0-A current flows through a 6.0- resistor. -What is the magnitude of v?

The figure shows a uniform,3.0-T magnetic field that is normal to the plane of a conducting,circular loop with a resistance of 1.5 and a radius of 0.024 m.The magnetic field is directed out of the paper as shown.Note: The area of the non-circular portion of the wire is considered negligible compared to that of the circular loop. -If the magnetic field is held constant at 3.0 T and the loop is pulled out of the region that contains the field in 0.2 s,at what rate is energy dissipated in R?

A flexible,circular conducting loop of radius 0.15 m and resistance 4.0 lies in a uniform magnetic field of 0.25 T.The loop is pulled on opposite sides by equal forces and stretched until its enclosed area is essentially zero m²,as suggested in the drawings.It takes 0.30 s to close the loop. -Which one of the following phrases best describes the direction of the induced magnetic field generated by the current induced in the loop while the loop is being stretched?