Induced Definition and 925 Threads

I'm doing some experiments, and I need to measure the current (and/or voltage) going through several loops of wire as a magnet slides through. The magnet slides parallel under the loops at a certain speed. I have a multimeter and an ammeter. The problem with the ammeter is that it's just a...

Homework Statement A circular loop made from a flexible, conducting wire is shrinking. Its radius as a function of time is . The loop is perpendicular to a steady, uniform magnetic field B . Find an expression for the induced ε in the loop at time t. Give your answer in terms of , , t, B and...

Homework Statement A WxH rectangular loop of wire, with resistance R, lies on a table a distance s from a separate long straight wire carrying a current I. If the loop is pulled to the right, parallel to the wire, with the speed v, then what is the magnitude of the current induced on the...

I would like to quantify the EMI on a circuit and I am confused on how to do that. I have two parallel wires that are laying on top of each other. I have tried to calculate the flux linkage and came up with: \Lambda = [l*\muo*I/(2pi)]*ln((d-a)/a) where a=radius of each wire...

Homework Statement Find the surface charge induced on an infinite conducting plate by a point charge +q at a distance a from the plate. The Attempt at a Solution As you probably know, this problem can be solved using the well-known fact that the induced electric field is equivalent to...

Homework Statement This is part of a lab I did, I am working on the writeup now. We placed a coil of wire inside of a Helmholtz pair, with 20V of 60Hz AC through the Helmholtz pair. The coil inside was connected to an oscilloscope and the induced voltages were recorded. I now need to...

OK, so we have a stick 91cm long which is accelerated by 1m/s/s in a magnetic field B= 0.606T. I need to find the induced voltage at time t = 288ms. So U = B/V which is B/(a*t) When i calculate i get 2 Volts which i think is too much. Plus the solution should be given in mV. Is this the...

Homework Statement A coil with 170 turns, a radius of 5.0 cm, and a resistance of 12 ohms surrounds a solenoid with 230 turns/cm and a radius of 4.7 cm; see the figure. The current in the solenoid changes at a constant rate from 0 to 1.8 A in 0.11 s. Calculate the magnitude and direction of...

Homework Statement A 32 turn circular coil of radius 4.60 cm and resistance 1.00 is placed in a magnetic field directed perpendicular to the plane of the coil. The magnitude of the magnetic field varies in time according to the expression B = 0.0100t + 0.0400t2, where t is in seconds and B is...

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure (the current is pointing in the left direction). a. there will be no induced emf and no induced current b. there will be a...

Homework Statement A single coil with a radius of .02m is placed inside a 3m long solenoid that has 600 turns. The radius of the solenoid is 0.15m. The plane of the coil is perpendicular to the axis of the solenoid. The solenoid is connected to a battery, an ammeter and a switch. The ammeter...

Homework Statement A magnet is dropped down each the copper and glass tube. What direction is the induced current in the copper and glass tube respectively? a)clockwise, clockwise b)clockwise, no induced current c)counter clockwise, clockwise d)counter clockwise, no induced current...

Homework Statement Suppose you have a coil that is a certain distance from a magnet. Now you move the coil towards the magnet (until it is on top of the magnet) at a certain speed. Then you do the same thing only faster. Will the total induced emf be the same for both tries? Aka should the...

Homework Statement The two solenoids in the figure are coaxial and fairly close to each other. While the resistance of the variable resistor in the left-hand solenoid is increased at a constant rate, the induced current through the resistor R will A - flow from a to b. B - flow from...

induced emf in secondary coil - help ASAP Please Homework Statement A very long, straight solenoid with a cross-sectional area of 6.00 cm2 is wound with 40.0 turns of wire per centimeter, and the windings carry a current of 0.250 A. A secondary winding of 2.00 turns encircles the solenoid...

Will this work in principal? When a current is induced into a coil, by way of a permanent magnet, the said coil will react in producing its' own flux field. Can the flux field produced further induce a current in, let's say, a separate/independent closed loop? Thanks

Hello. 3) A step up transformer increases the mains voltage of 230V to 5000V. a) calculate the ratio Number of primary turns/Number of secondary Turns I know the formula input voltage/output voltage = Primary turn/ Secondary Turns So i did 230/5000 = 0.046. This as a fraction is...

\xi = - \frac{dB}{dt} Is the emf induced by a changing flux. Is the current created by this emf conventional current? For example. Say there is a square loop in the plane of this page, with a decreasing magnetic field going INTO this page. This creates a clockwise current to battle the change...

Using a PMs' field and inducing a primary coil which is coupled with an independent coil of equal configuration to the primary. Would this secondary flux field be opposite and of equal EMForce? If so, Equal to the PMs' strength or the primarys' EMForce? Thanks Robin07

An elastic conducting material is stretched into a horizontal circular loop of radius 20 cm and placed in a magnetic field of strength 0.5 T, directed vertically downwards. a. What is the magnetic flux through the loop? b. When released, the radius of the loop decreases at an initial rate...

Homework Statement A generator is constructed by rotating a coil of N turns in a magnetic field B at a frequency f. The internal resistance of the coil is R and the cross sectional area of the coil is A. Which of the following statements are true? (Give ALL correct answers, i.e., B, AC...

Homework Statement A circular coil, with radius of 10 cm, and 25 turns, rotates in a constant magnetic field of strength 2.4 T, with the axis of rotation perpendicular to the direction of the magnetic field. (a question about finding the induced voltage- 5.92 V) part C. If the...

I have been trying, but I still have 3 problems I can't get. 1)A simple generator has a 600 loop square coil 18.0 cm. on a side. How fast (in rev/s.) must it turn in a 0.730 T. field to produce a 120-V. peak output? I think I need to use the equation Emax=NBAw. N=600 B=.730 A=.0324...

Hello everyone :smile: I got a small question. In an electric motor when the coil rotates isn't this a change of magnetic flux. So wouldn't there be an induced emf in the coil? Any help would be appreciated. Thanks :smile:

Homework Statement A square loop, 5.3 m on a side, is made of copper wire, 0.9 mm in radius. A 3.2 T magnetic field, perpindicular to the loop is increasing at the rate of 0.29 T/s. The resistivity of copper is 1.7 x 10^-8 ohm*m. Find the induced current. Answer in units of A. Homework...

Homework Statement The sketches below show a circular coil and a permanent magnet; the arrows indicate both the magnitude and the direction of the velocities of the magnet and coil. In which situations will the induced voltage (and hence the current) in the loop be zero? (Enter your answer...

hi, everyone, now I am trying to deposite some metal layers on micro-scale cantilever surface on the purpose of bending it under the residual stress caused by metal deposition. I read some literatures which mentioned and even gave the exact value of residual stress happened in both the...

Homework Statement A rectangular coil of 150 turns has dimensions of 23 x 70 cm and is located in a uniform 3 T magnetic field. In 1.2 s, the plane of the coil is rotated from a position where it makes an angle of 15° with the magnetic field to a position where it makes an angle of 72°...

A loop of area 4 cm2 has its plane parallel to the field lines of the magnetic field, B = 0.6 T, as shown in the figure. The loop is pulled in the opposite direction of the field with a constant velocity of v = 6 m/s. http://img375.imageshack.us/img375/4139/picbs3.th.jpg A. What is the...

Homework Statement http://img164.imageshack.us/img164/3313/qqqqo3.jpg Find the total magnetic flux through the coil at t=0 Given that the rate of change of flux at any time,t, is equal to 2 \pi f \phi sin 2 \pi ft, find the maximum instanteous value of the induced emf at any time & the...

Homework Statement a single square loop of high resistivity wire ( rho = 10^-6 ohm-meters) is placed in a constant magnetic field B of 0.3 Teslas and oriented so that the axis of rotation of the loop is perpendicular to B and in the plane of the loop. the loop rotates with an angular frequency...

Homework Statement An coil has 4000 turns of wire and a mean area of cross-section 25cm^2. A magnetic field of flux density 0.16T passes through it. When the magnetic field is reduced steadily to zero in 0.0050s, emf is induced across the terminals of the coil. Calculate the value of this...

if the Earth is one big magnet, why there is not current induced in our selfs? I mean, why there is not electromagnetic induction in the human body?

Homework Statement Please see the attached figure. We have two parallel long wires carrying a time varying current I(t), but running in opposite directions. We wish to know the induced electric field between the wires, but only in the plane containing the two wires. Sorry that I don't know...

Homework Statement The photograph shows a transformer which has been cut in half. The transformer consists of primary and secondary coils wound around the same laminated iron core. The diagram shows a cross-section of the iron core and the two coils. One coil consists of a few turns of thick...

Homework Statement A metal ring 4.50 cm in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. These magnets produce an initial uniform field of 1.12 T between them but are gradually pulled apart, causing this...

Say we have an induced circuit. My book states that we cannot use the loop rule on an induced circuit because we cannot define a potential difference in the circuit. If the potential difference is undefined how can current exist? There's probably a really obvious answer, but I'm not seeing it.

Homework Statement A point charge q is located in the xy plane near two grounded conducting planes intersecting at right angles as shown in the Figure. The z axis lies along the line of intersection of the planes. Find and justify (mathematically show) the force acting on this charge q...

Hello, I am currently working through Faraday's Law and I am confused when my two textbooks don't explain how they set the polarity of V_{emf}, particularly when they say "the sign convention for V_{emf} is arbitrary in that it depends on the assumed direction for dS". How is the polarity...

A coil with 240 turns enclosing an area of 13.7 cm^2 is rotated in a time interval of 3.70×10^-2 s from a position where its plane is perpendicular to the Earth's magnetic field to one where its plane is parallel to the field. The Earth's magnetic field at the lab location is 5.9×10−5 T ...

Homework Statement A circular loop of wire is rotated at constant angular speed around an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if the induced emf is to be zero...

The circuit is shown below: Find the current through section PQ of length a = 65.0cm. The circuit is located in a magnetic field whose magnitude varies with time according to the expression B = (1.00 x 10^-3T/s)t. Assume the resistance per length of the wire is 0.100 Ohm/meter...

A circular loop of wire has a changing magnetic field running through it...however, the magnetic field is not touching the wire; its contained so that it simply runs through the loop without touching the wire. Apparently, there is still an emf through the wire even though the magnetic field is...

A circular loop of wire has a changing magnetic field running through it...however, the magnetic field is not touching the wire; its contained so that it simply runs through the loop without touching the wire. Apparently, there is still an emf through the wire even though the magnetic field is...

1. Is it induce e.m.f is a force? 2. What is the eddy current?

There is something on Lenz's law about induced current and the magnetic field that I don't quite understand. "Apply Lenz's law that when the magnet is brought near the coil, the magnet's magnetic field through the coil increases, and therefore the flux increases." Here, why the magnet's...

Ok, this may borderline a homework problem, but I'm not quite grasping the concept of induced electric fields. So let's say that they exist a wire loop and solenoid. The switch in the circuit containing the solenoid is originally open and then closed. At this instant, we induce an emf in the...

Hey everyone, I'm having trouble with b and c and any help would be appreciated! I attached two pictures on the bottom (one of the entire problem and one of just the diagram) Homework Statement Five loops are formed of copper wire of the same gauge (cross-sectional area). Loops 1-4 are...

Homework Statement A metal ring 4.6 cm. in diameter is placed between the north and south poles of large magnets with the plane of its area perpendicular to the magnetic field. These magnets produce an initial uniform field of 1.12 T between them but are gradually pulled apart, causing this...

[SOLVED] Griffiths induced charge Homework Statement I am so insanely confused about induced charge. Griffiths does this problem in which a charge q is held a distance d above an infinite grounded conducting plane and then he calculates that the induced charge on the plane is -q (section...