Two<br>vectors Å and °B are such that A = 2<br>and A-B-C find the angle between them

A coil is wrapped with 300 turns of wire on the perimeter of a circular frame (radius = 8.0 cm). Each turn has the same area, eq

MAVERICK [17]

Answer:

Approximately 18 volts when the magnetic field strength increases from $\rm 20\; mT$ to $\rm 80\;mT$ at a constant rate.

Explanation:

By the Faraday's Law of Induction, the EMF $\epsilon$ that a changing magnetic flux induces in a coil is:

$\displaystyle \epsilon = N \cdot \frac{d\phi}{dt}$ ,

where

$N$ is the number of turns in the coil, and
$\displaystyle \frac{d\phi}{dt}$ is the rate of change in magnetic flux through this coil.

However, for a coil the magnetic flux $\phi$ is equal to

$\phi = B \cdot A\cdot \cos{\theta}$ ,

where

$B$ is the magnetic field strength at the coil, and
$A\cdot \cos{\theta}$ is the area of the coil perpendicular to the magnetic field.

For this coil, the magnetic field is perpendicular to coil, so $\theta = 0$ and $A\cdot \cos{\theta} = A$ . The area of this circular coil is equal to $\pi\cdot r^{2} = \pi\times 8.0\times 10^{-2}\approx \rm 0.0201062\; m^{2}$ .

$A\cdot \cos{\theta} = A$ doesn't change, so the rate of change in the magnetic flux $\phi$ through the coil depends only on the rate of change in the magnetic field strength $B$ . The size of the magnetic field at the instant that $B = \rm 50\; mT$ will not matter as long as the rate of change in $B$ is constant.

$\displaystyle \begin{aligned} \frac{d\phi}{dt} &= \frac{\Delta B}{\Delta t}\times A \\&= \rm \frac{80\times 10^{-3}\; T- 20\times 10^{-3}\; T}{20\times 10^{-3}\; s}\times 0.0201062\;m^{2}\\&= \rm 0.0603186\; T\cdot m^{2}\cdot s^{-1}\end{aligned}$ .

As a result,

$\displaystyle \epsilon = N \cdot \frac{d\phi}{dt} = \rm 300 \times 0.0603186\; T\cdot m^{2}\cdot s^{-1} \approx 18\; V$ .

9 0

3 years ago

May I please get some help?

xxMikexx [17]

B is the correct q2ureire awej\

3 0

2 years ago

Using a coil made of 219 turns of single‑strand copper wire, you use a motor to rotate the coil at a constant angular speed of 9

mylen [45]

Answer:

0.0222T

Explanation:

Frequency (f) =90 rev/s

Voltage = 1.15 v

Radius of coil = 1.00cm

= 0.01m

No of turns of wire (N) = 291

ω = 2πf

ω = 2π(90)

ω = 180π

A(t)= πr².sin ωt

= π(0.01)². Sin180πt

= 0.0001π.sin180πt

Differentiate A(t) with respect to t

dA/dt = 0.0001π . 180π . cos 180πt

EMF = - NB(dA/dt)

B = EMF/N(dA/dt)

B = 1.15/ -291(0.0001π . 180π . cos 180πt)

At the moment of induced voltage, cos180π = 1

B = 1.15/ -291(0.0001π . 180π . 1)

B = 1.15/ -51.7

B = 0.0222 T

The strength of the magnetic field = 0.0222T

6 0

3 years ago

Someone fires a slingshot at a target that is far enough away to take 1.4 seconds to reach. How far below does the target does t

Korolek [52]

There is not enough information to answer the question

6 0

2 years ago

A hard rubber rod is rubbed with wool and thus gains an approximately uniform net negative charge. The rubber rod is then suspen

grandymaker [24]

Answer:

The acrylic rod gains a net negative charge by coming in contact with the hard rubber rod. This is because when brought in contact with the rubber rod some of the excess electrons which are responsible for the negative charge on the rubber rod gets deposited on the acrylic material. Electrons generally will be deposited more on a body where there is more space to accommodate them. So the magnitude of charge that gets deposited on the acrylic material depends on the free sites available to the incoming electrons.

Explanation:

When the rubber rod is scrapped the net charge on the rubber rod changes to positive or negative depending on if it is gaining or loosing electrons. The act scrapping happens because of friction and friction causes transfer of charges between two different materials. The material that loses electronic gains a net positive charge and the material that accepts gains a net negative charge.

4 0

2 years ago

Twovectors Å and °B are such that A = 2and A-B-C find the angle between them​

Twovectors Å and °B are such that A = 2and A-B-C find the angle between them