Physics, 30.10.2019 06:31 lewisf5929

Ablock in the shape of a rectangular solid has a cross-sectional area of 4.84 cm2 across its width, a front-to-rear length of 14.0 cm, and a resistance of 1250 ω. the block's material contains 6.90 × 1022 conduction electrons/m3. a potential difference of 28.4 v is maintained between its front and rear faces. (a) what is the current in the block? (b) if the current density is uniform, what is its magnitude? what are (c) the drift velocity of the conduction electrons and (d) the magnitude of the electric field in the block?

Answers: 3

Show answers

Answers

Answer from: nicole667

(a) I=0.0227 A

(b) $J=46.9422 A.m^{-2}$

(d) $E= 202.8571 V.m^{-1}$

Explanation:

Given is a solid cube having following properties:

cross-sectional area, a = 4.84 cm^2

length of the cube perpendicular to the given area, l= 14 cm

resistance, $R=1250 \Omega$ potential difference across the length, V = 28.4 V electron density, $N= 6.9\times 10^{22} m^{-3}$

We, know the formula:

Current, $I=\frac{V}{R}$

Putting the respective values:

$I= \frac{28.4}{1250} \\\\I=0.0227 A$

Current density, $J= \frac{I}{a}$

Putting the respective values:

$J=\frac{0.0227}{4.84\times 10^{-4}}\\\\J=46.9422 A.m^{-2}$

Drift velocity, $v_d= \frac{I}{N.e.a}$

where, e is the charge on an electron.

Putting the respective values:

$v_d= \frac{0.0227}{6.9\times 10^{22}\times 1.6\times 10^{-19}\times 4.84\times 10^{-4}}$

$v_d= 0.0042 m.s^{-1}$

Electric field, $E= \frac{V}{l}$

$\Rightarrow E=\frac{28.4}{14\times 10^{-2}} \\\\\Rightarrow E= 202.8571 V.m^{-1}$

Answer from: alex7881

(a) I = 0.023 A

(b) J = $46.9\ A/m^{2}$

(d) E = 202.85 N/C

Solution:

As per the question:

Cross-sectional area, A = $4.84\ cm^{2} = 4.84\times 10^{- 4}\ m^{2}$

Length of the block, L = 14.0 cm = 0.14 m

R = 1250 $\Omega$

Potential Difference, V = $28.4\ V$

N = $6.90\times 10^{22}\ conduction\ electrons/m^{3}$

Now,

(a) Current in the block is given by:

$I = \frac{V}{R}$

$I = \frac{28.4}{1250} = 0.023\ A$

(b) Current density is given by:

$J = \frac{I}{A} = \frac{V}{AR} = \frac{28.4}{4.84\times 10^{- 4}\times 1250} = 46.9\ A/m^{2}$

$v_{d} = \frac{J}{ne} = \frac{ALJ}{Ne} = \frac{VAL}{NeRA} = \frac{VL}{NeR}$

where

n = $\frac{1}{AL}$

$v_{d} = \frac{28.4\times 0.14}{6.90\times 10^{22}\times 1.6\times 10^{- 19}\times 1250} = 2.88\times 10^{- 7}\ m/s$

(d) The magnitude of electric field is given by:

$E = \frac{V}{L} = \frac{28.4}{0.14} = 202.85\ N/C$

Answer from: Quest

the cellphone, they would then know if the killer would have contacted them or always hated them. or if it was a breakup. but if that is not the case, then it would be the clothing. to put in a bullet, it would have to be put in by hands. hands have finger prints which, would have giving you the answer of who done it.

explanation:

Answer from: Quest

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

Another question on Physics

Physics, 21.06.2019 20:00

Player kicks a soccer ball from ground level and sends it flying at an angle of 30 degrees at a speed of 26 m/s. what is the horizontal velocity component of the ball to the nearest tenth of a m/s?

Answers: 2

Answer

Physics, 22.06.2019 04:00

What is the final velocity of the initial velocity of 25 and -50?

Answers: 2

Answer

Physics, 22.06.2019 09:00

As a pendulum bob swings back and forth several times, the maximum height it reaches becomes less and less. this is because more and more of the pendulum bob's energy is being transformed into a. heat energy b. kinetic energy c. potential energy d. kinetic energy and potential energy

Answers: 2

Answer

Physics, 22.06.2019 12:50

The combining of light nuclei is called blank. blank as in not actually blank. you know what im tryin to say.

Answers: 1

Answer

You know the right answer?

Ablock in the shape of a rectangular solid has a cross-sectional area of 4.84 cm2 across its width,...

Questions