All categories

3 years ago

What is the difference between a bar magnet and an electromagnet? (check all that are

Physics

1 answer:

lukranit [14]3 years ago

5 0

Answer:

D and A

Explanation:

Hint The basic difference between them is that a bar magnet is a permanent magnet whereas an electromagnet is a temporary magnet. An electromagnet is formed when an electric current is passed through wires wound around soft metalcore. An electromagnet loses its magnetism once the current flow is stopped.

You might be interested in

Two facing surfaces of two large parallel conducting plates separated by 8.5 cm have uniform surface charge densities such that

elena-s [515]

Answer:

positive plate

E = 5.764 KV / m

W = 490eV or 7.85 * 10^-17 J

E_p = 4.74 *10^(-12) eV

E_k = 490 eV

Explanation:

part a

The potential difference between two plates = 490 V

Distance between two plates = 8.5 cm

Answer: The positive plate is at higher potential because of convention.

part b

Electric Field between the plates

E = V / d

E = 490 / 0.085 = 5.764 KV / m

Answer: Electric Field between the plates E = 5.764 KV / m

part c

Work done by electric field

W = V*q

W = 490 * 1.602*10^-19

W = 7.85 * 10^-17 J

or W = 490 eV

Answer: Work done by electric field W = 490eV or 7.85 * 10^-17 J

part d

Potential Energy of an electron gained:

E_p = m_e * g * d / (1.602*10^-19)

E_p = 9.109*10^-31* 9.81 * 0.085 / (1.602*10^-19)

E_p = 4.74 *10^(-12) eV

Very very small E_p approximately 0

Answer: Potential Energy of an electron gained E_p = 4.74 *10^(-12) eV or 0.

part e

Kinetic Energy of an electron gained:

W - E_p = E_k

E_k = 490eV - 4.74*10^(-12)eV

E_k = 490 eV

Answer: Kinetic Energy of an electron gained E_k = 490 eV

7 0

4 years ago

A 80 kg skier grips a moving rope that is powered by an engine and is pulled at constant speed to the top of a 25 degrees hill.

zloy xaker [14]

Answer:

$P=28.085\,hp$

Explanation:

Given that:

mass of 1 skier, $m=80kg$

inclination of hill, $\theta=25^{\circ}$

length of inclined slope, $l=220m$

time taken to reach the top of hill, $t=2.3 min= 138 s$

coefficient of friction, $\mu=0.15$

Now, force normal to the inclined plane:

$F_N=m.g.cos\theta$

$F_N=80\times 9.8\times cos25^{\circ}$

$F_N=710.54\,N$

Frictional force:

$f=\mu.F_N$

$f=0.15\times 710.54$

$f=106.58\,N$

The component of weight along the inclined plane:

$W_l=m.g.sin\theta$

$W_l=80\times 9.8\times sin25^{\circ}$

$W_l=331.33\,N$

Now the total force required along the inclination to move at the top of hill:

$F=f+W_l$

$F=106.58+331.33$

$F=437.91\,N$

Hence the work done:

$W=F.l$

$W=437.91\times 220$

$W=96340.80\,J$

Now power:

$P=\frac{W}{t}$

$P=\frac{96340.80}{138}$

$P=698.12\,W$

So, power required for 30 such bodies:

$P=30\times 698.12$

$P=20943.65\,W$

$P=\frac{20943.65}{745.7}$

$P=28.085\,hp$

8 0

3 years ago

The subject of the second part of messiah is:

Zielflug [23.3K]

The second part is about his suffering and the spread of his doctrine.

5 0

4 years ago

An electric current in a conductor varies with time according to the expression I(t) = 100 sin (120πt) , where I is in amperes a

Mice21 [21]

The total charge passing a given point in the conductor from t = 0 to t = 1/240 s is 12000π Coulombs

<h3>Total charge through a conductor</h3>

A conductor is a substance that allow current and electricity to pass through it.

The expression that will be used to calculate the current is expressed s:

I(t) = 100 sin (120πt)

where

I is in amperes and t is in seconds.

Since dQ = Idt = I(t) = 100 sin (120πt)

On integrating

Q = 100*120πcos(120πt) |¹/¹²⁴⁰₀

Substitute the limits

Q = 100 * 120π

Q = 12000π Coulombs

Hence the total charge passing a given point in the conductor from t = 0 to t = 1/240 s is 12000π Coulombs

Learn more on total charge through a conductor here: brainly.com/question/15083960

#SPJ4

7 0

2 years ago

a washing machine uses 750 watts of power and costs $0.15 per kilowatt-hour. How much does it cost to run a washing machine for

Alja [10]

Answer:$0.1125

Explanation:

power=750 watts

Power=750/1000=0.75 kilowatts

$0.15 for 1 kilowatts-hour

$h for 0.75 kilowatts-hour

$h=(0.75 x 0.15)

$h=$0.1125

7 0

3 years ago

Read 2 more answers