### DC Circuits: Time Varing current and Voltages

See the attached file with 4 circuit problems.

Explore BrainMass

- Anthropology
- Art, Music, and Creative Writing
- Biology
- Business
- Chemistry
- Computer Science
- Drama, Film, and Mass Communication
- Earth Sciences
- Economics
- Education
- Engineering
- English Language and Literature
- Gender Studies
- Health Sciences
- History
- International Development
- Languages
- Law
- Mathematics
- Philosophy
- Physics
- Political Science
- Psychology
- Religious Studies
- Social Work
- Sociology
- Statistics

See the attached file with 4 circuit problems.

(See attached file for full problem description with proper symbols and diagrams) --- 3.1 A long wire carries a current of 2 A along the +z axis. Calculate B in free space at (3,4,9). 3.2 Inside a long conductor of radius a, the magnetic field is H = 5 rho;/(2pi a2) a(phi) A/m. (a) Determine the current density J. (b) D

See attached file for proper format of formulas. A loop of 500 turns is placed in a magnetic field that follows the equation: (See attachment) The radius of the loop is 0.75 m. a) What is the relation of the induced emf in that loop? b) What is the induced emf of the loop at 2 sec? c) If the wire has a resistance o

(See attached file for full problem description) --- Refer to diagram below: 1. Use thevenin's theorem to calculate the thevenin emf and impedance for the circuit contained in the box to the left of the terminals A&B. Assume that L is a pure inductor. 2. Sketch the complete thevenin circuit plus load and calculate:

Transcranial magnetic stimulation (TMS) is a noninvasive method for studying brain function, and possibly for treatment as well. In this technique, a conducting loop is held near a person's head. When the current in the loop is changed rapidly, the magnetic field it creates can change at a rate of {see attachment}. This rapidly

A constant magnetic field passes through a single rectangular loop whose dimensions are 0.35 m x 0.55 m. The magnetic field has a magnitude of 2.1 T and is inclined at an angle of 70° with respect to the normal to the plane of the loop. (a) If the magnetic field decreases to zero in a time of 0.52 s, what is the magnitud

A 60-Hz 24-kV 250-MVA Y-Connected salient-pole synchronous generator (Xd=1.75 per unit, Xq=1.40 per unit) is operating with a phase-A to a neutral voltage of 14 cos wt kV and a phase-A current of 5.75 cos wt kA; the currents and voltages are balanced at three-phase. The rotor angle is known to be wt+37 degrees. a) Draw a pha

1. A proton of charge + 1.6 x 10^(-19) C and mass 1.67 x 10(-27)kg is introduced into a region of B = 1.5 T with an initial velocity of 1.25 x 10^6 m/s perpendicular to B. What is the radius of the proton's path? 2. A coil 17 cm in diameter and wound with 12 turns of wire is placed with the plane of the coil at right angles t

Determine the voltage drop (from top to bottom) across the 16ohm resistor. Also, determine the voltage drop (from top to bottom) across the 4ohm resistor. Referring to the circuit, what is the voltage v? Show how you arrived at your answer.

A 25-turn circular coil of wire has diameter 1.00 m. It is placed with its axis along the direction of the Earth's magnetic field of 50.0 μT, and then in 0.200 s it is flipped 180°. An average emf of what magnitude is generated in the coil?

The magnetic field perpendicular to a circular loop of wire 17.6cm in diameter is changed from +0.510 T to -0.450 T in 117rms, where + means the field points away from an observer and - toward the observer. Calculate the induced emf.

A 6.30cm diameter wire coil is initially oriented so that its plane is perpendicular to a magnetic field of 0.740T pointing up. During the course of 0.130s, the field is changed to one of 0.310 T pointing down. What is the average induced emf in the coil?

A bar is moving across a open-ended loop with resistance R in a presence of a constant perpendicular magnetic field. a. At what speed should the bar be moved to produce a current of 0.500 A? b. What is the motional emf? c. What is the power dissipated by the resistor? d. What force must be applied to the bar?

A metal bar of mass m and length L slides without friction but with good electrical contact between two vertical metal posts. The bar and posts have negligible resistance. The posts are connected at the bottom by a resistor R. Assume the bar falls at constant speed v, and that there is a magnetic field coming out of the page.

Imagine that we have two metal rails 20 cm apart connected by a light bulb. The rails are placed in a 1.0 T magnetic field oriented vertically downward. We then constrain a bar to slide on the rails toward the lightbulb in this magnetic field. How fast do we have to move the bar to put a voltage difference of 3.0 V across the

The current in a 48.1 mH inductor changes with time as I = bt^2 - at. With a = 2.7 A/s and b = 3 A/s^2, find the magnitude of the induced emf at t = .992 s. Units of V At what time is the emf zero? Units of s

See attached file. In the figure, ABCD is a conducting wire. A conducting bar EF is laid on top of the wire and slid toward BC with a speed of .030 m/sec. A constant magnetic field B of 2.0*10^(-5)Tesla points out of the paper. The length of BC is 1.5m and the distance of the bar from EF is initially 2.0m. 1) What is the i

A 5 meter long copper wire, with a cross sectional area of 1.0mm^2 is bent into a circle. This loop of wire is mounted in a vertical plane between the poles of a magnet. This magnet is aligned so that its field points in a horizontal direction from the west to the east; the magnitude of this field is 7.25*10^(-4)T. The loop of w

See attached file. A1. Find the current through and potential difference across each resistor in the following circuit.

A rod of length l is pivoted at one end rotates with uniform angular velocity w in a uniform magnetic field of intensity B. The magnetic fluxes are perpendicular to the plane of rotation of rod. Calculate the induced EMF across the two ends of rod.

PART ONE: A battery that supplies an emf of 6.0 V has an internal resistance of 0.20 ohm. It is connected to a load resistor of 8.8 ohms. The total Current in the entire circuit is: A) less than 0.25 A B) between 0.25 A and 0.50 A C) between 0.50 A and 1.0 A D) greater than 1.0 A PART TWO: A battery of fou

See attached files. 1. At a certain location, Earth has a magnetic field of 0.6*10^4T pointing 75 degrees below the horixontal in a north-south plane. A 10m long straight wire carries a 15A current. A) If the current is directed horizontally toward the east, what are the magnitude and direction of the magnetic force on th

Just need numaric answer for these mechanic questions. see attached

See attached file for problems of resistance, tungsten filaments, current, emf.

The mutual inductance of two coils is 0.750 H. How do I find the average emf induced in the secondary if the current in the primary reaches 6.00 A in 0.0300s?

The length of a conductor linking a magnetic field is 0.060m, and the flux density of the field is 0.040 N/Am The conductor is moving down through the flux with a velocity of 1.5 m/s. What is the induced emf?

A circular current loop made of flexible wire is located in a magnetic field B; you may keep B constant or vary it. Describe three ways an emf can be induced in the loop.

A coil of 500 turns is wound on a wooden ring having a mean diameter of 8 cm and a cross sectional area of 1.5 cm^2. Assuming relative permeability of wood is 1, calculate the self-inductance of the coil and the emf induced in it when the direction of a DC current of 5A flowing in it is reversed in 0.2 sec?