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EMF

EMF induced in a conductor moving in a magnetic field.

EMF in a Bullet. At the equator, the earth's magnetic field is approximately horizontal and is directed toward the north and has a value of X. Part A Estimate the emf induced between the top and bottom of a bullet shot horizontally at a target on the equator if the bullet is shot toward the east. Assume the bullet has a len

Find the current in the bulb

In the circuit of the figure attached, each resistor represents a light bulb. Let R_1=R_2=R_3=R_4= 4.27 ohms and let the EMF be 9.00 V. 1) Find the current in the bulb R_2: 2) Find the current in the bulb R_3: 3) Find the current in the bulb R_4:

Current as a Function of Time for a Circuit

Let us now consider a different RC circuit. This time, the capacitor is initially charged (q(t) = q_0), and there is no source of EMF in the circuit. We will assume that the top plate of the capacitor initially holds positive charge. For this circuit, Kirchoff's loop rule gives IR + q/C = 0, or IR = -q/C. Find the current

Time for capacitor charge to reach 99.9% maximum

Consider a series circuit containing a resistor of resistance R and a capacitor of capacitance C connected to a source of EMF E with negligible internal resistance. The wires are also assumed to have zero resistance. Initially, the switch is open and the capacitor discharged. Let us try to understand the processes that take

Electromagnetic Induction and induced EMF

Magnetic resonance imaging (MRI) is a medical technique for producing pictures of the interior of the body. The patient is placed within a strong magnetic field. One safety concern is what would happen to the positively and negatively charged particles in the body fluids if an equipment failure caused the magnetic field to be sh

output EMF of a generator

(See attached file for full problem description) 4. The drawing below shows a plot of the output emf of a generator as a function of time t. The coil of this device has a cross-secontal area per turn of 0.040 m2 and contains 136 turns. Find a. the frequency of the generator in Herz b. the angular speed in rad/s c. the magnit

Capacity, charge and voltage

The radii of curvature of the spheres of a spherical capacitor is given and to find the charge, charge density and work done when it is connected to a battery. See attached file for full problem description.

Inductance of a Solenoid

A long solenoid of length 8m with a cross-sectional area of 5.0x10^-5 m^2 contains 52,000 turns. 1) Find the self-inductance of the solenoid, assuming that the core is air. 2) If the current in the winding starts at 0 A and is increased steadily to 1.5 A in a time of 0.20 sec, what is the EMF induced in the solenoid?

Faraday's Laws of Electromagnetic Induction

A coil of wire with 40 turns is held stationary between the poles of an electromagnet. The field in the electromagnet is increased from 0 to 0.75T in a time of 225 seconds. What is the magnitude of the induced EMF in the coil if the angle that the plane of the coil makes with the field is 30 degrees?

Induced emf on a rotating rod in a uniform magnetic field

A uniform rod of length l is rotating with angular velocity w around the axis passing through the rod end and parallel to the field line of uniform magnetic field B. Derive an expression for potential difference across the rod. (For diagram please see the JPG file)

Assorted Problem Set on Currents

See the attached file. 1. a) The magnitude of the earth's magnetic field at the surface of the earth is slightly less than one gauss.( I answered False and the answer was true) b) The torque exerted on a current loop by a uniform field tends to orient the plane of the loop perpendicular to the magnetic field.(I answered fals

RL Circuits: Growth and decay of current in inductor

See attached circuit. Note current source is 2A,Resistors are 2 Ohms, Inductor 2H. Assume that the switch has been open for a long time and that it closes at t=0 sec. The switch remains closed thereafter. How do I solve for Vx(t) and Ix(t)?

Electromagnetic Induction: EMF in a ring outside a solenoid

A long solenoid is wound with 500 turns per meter and current in its windings is increasing at the rate of 100A/s. The Cross-sectional area of the solenoid is 4.0cm^2. If the solenoid is encircled at its center by a circular conducting loop, Find the magnitude of the induced electric field within the outside conduction loop if

Electromagnetic Induction: Induced EMF in a rotating loop

1. A rectangular loop with surface area A lies in the x,y-plane with two sides parallel to the x-axis and the other two parallel to the y-axis in the presence of a uniform magnetic field with a magnitude B directed along the positive x-axis. The loop is made to rotate around an axis that is parallel to the y-axis and bisects the

2 Problems

1. What is the definition of displacement current and how does it arise? Does displacement current have any real significance? Explain 2. Write down the maxwell's equations of electromagnetism, and state the laws they represent. Explain the meaning of all the symbols used.

RCL series circuit

When an RCL series circuit is connected to a 120 V rms 60 Hz line, the rms current is 11.0 A and the current leads the emf by 45 degrees. a) Find the power supplied to the circuit. b) What is the resistance? c) If the inductance is 0..05H, find the capacitance. d) What capacitance would you add, and how, to make the po

Calculating the current of a circuit

A 50.0 H inductor and a 12.5 ohm resistor are connected in a series. A power source of constant 22.5 volts is applied across the series RL circuit elements at time t=0. What is the current in the circuit 10.0 seconds after the power is applied?

Lenz's Law for Magnetic Flux

The magnetic flux through the loop increases according to the relation (see attachment for remainder of the question). a) What is the magnitude of the emf induced in the loop when t= 2.05? b) Is the direction of the current through R to the right or left?

Induction and Energy Transfer

A metal rod is forced to move constant velocity V along two parallel metal rails, connected with a strip of metal at one end. A magnetic field of magnitude B = .350T points out of the page. a) if the rails are separated by a 25.0 cm and the speed of the rod is 55.0 cm/s, what emf is generated? b) if the rod has a resista

Electromagnetic Induction: Induced EMF and Current

Two parallel loops of wire having the same common axis. The smaller loop of (raduis r ) and is above the larger loop (raduis R) by a distance X>>R. The magnetic field due to the counterclockwise current i in the larger loop is nearly uniform throughout the smaller loop. Suppose that x is increasing at a constant rate dx/dt = v.

DC Circuits: Time Varying Current and Voltages

Consider the circuit of Figure P4.18 in which the switch has been open for a long time prior to t=-0. Determine the values of vc(t) before t=0 and a long time after t=0. Also, determine the time constant after the switch closes and expressions for vc(t). Sketch vc(t) to scale versus time for -2 <= t <= 5. Consider the circuit

16 good questions on electromagnetism

(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

loop of 500 turns is placed in a magnetic field

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

EMF Thevenin's Diagram

(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:

Changing magnetic field

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

Faraday's Law of Electromagnetic Induction 2

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

Phasor Diagram for Synchronous Generator

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