All categories

3 years ago

Does current in Helmholtz coils flow in the same or opposite direction through each coil? Explain.

Physics

1 answer:

zhenek [66]3 years ago

5 0

To get a uniform field in the central region between the coils, current flows in the same direction in each.

You might be interested in

How did Niels Bohr change the atomic model based on his experimental results?

Alexus [3.1K]

Answer: Find the answer in the explanation

Explanation:

Bohr postulated that :

1.) Electrons revolve in specific circular orbits around the nucleus and these orbits can be represented by the letters K, L, M, N.

2.) Electrons revolving in a particular orbit are in a stationary state. They can neither gain energy nor loose energy. 3.) But if an electron jumps from an higher orbit to a lower orbit it will emit energy in the form of radiations. Also if an electron jumps from lower orbit to a higher orbit it excites and absorbs energy in the form of radiations.

4.) Neil Bohr experimental findings about angular momentum of an electron shows more light on the stability of atom and the line spectrum of hydrogen atom

8 0

4 years ago

A thin spherical spherical shell of radius R which carried a uniform surface charge density σ. Write an expression for the volum

ozzi

Answer:

Explanation:

From the given information:

We know that the thin spherical shell is on a uniform surface which implies that both the inside and outside the charge of the sphere are equal, Then

The volume charge distribution relates to the radial direction at r = R

∴

$\rho (r) \ \alpha \ \delta (r -R)$

$\rho (r) = k \ \delta (r -R) \ \ at \ \ (r = R)$

$\rho (r) = 0\ \ since \ r< R \ \ or \ \ r>R---- (1)$

To find the constant k, we examine the total charge Q which is:

$Q = \int \rho (r) \ dV = \int \sigma \times dA$

$Q = \int \rho (r) \ dV = \sigma \times4 \pi R^2$

∴

$\int ^{2 \pi}_{0} \int ^{\pi}_{0} \int ^{R}_{0} \rho (r) r^2sin \theta \ dr \ d\theta \ d\phi = \sigma \times 4 \pi R^2$

$\int^{2 \pi}_{0} d \phi* \int ^{\pi}_{0} \ sin \theta d \theta * \int ^{R}_{0} k \delta (r -R) * r^2dr = \sigma \times 4 \pi R^2$

$(2 \pi)(2) * \int ^{R}_{0} k \delta (r -R) * r^2dr = \sigma \times 4 \pi R^2$

Thus;

$k * 4 \pi \int ^{R}_{0} \delta (r -R) * r^2dr = \sigma \times R^2$

$k * \int ^{R}_{0} \delta (r -R) r^2dr = \sigma \times R^2$

$k * R^2= \sigma \times R^2$

$k = R^2 --- (2)$

Hence, from equation (1), if k = $\sigma$

$\mathbf{\rho (r) = \delta* \delta (r -R) \ \ at \ \ (r=R)}$

$\mathbf{\rho (r) =0 \ \ at \ \ rR}$

To verify the units:

$\mathbf{\rho (r) =\sigma \ * \ \delta (r-R)}$

↓ ↓ ↓

c/m³ c/m³ × 1/m

Thus, the units are verified.

The integrated charge Q

$Q = \int \rho (r) \ dV \\ \\ Q = \int ^{2 \ \pi}_{0} \int ^{\pi}_{0} \int ^R_0 \rho (r) \ \ r^2 \ \ sin \theta \ dr \ d\theta \ d \phi \\ \\ Q = \int ^{2 \pi}_{0} \ d \phi \int ^{\pi}_{0} \ sin \theta \int ^R_{0} \rho (r) r^2 \ dr$

$Q = (2 \pi) (2) \int ^R_0 \sigma * \delta (r-R) r^2 \ dr$

$Q = 4 \pi \sigma \int ^R_0 * \delta (r-R) r^2 \ dr$

$Q = 4 \pi \sigma *R^2$ since $( \int ^{xo}_{0} (x -x_o) f(x) \ dx = f(x_o) )$

$\mathbf{Q = 4 \pi R^2 \sigma }$

6 0

3 years ago

Elena makes a table to organize the functions of electric motor components.

Naddik [55]

Answer:

C. X: Allows current to flow into the commutator

Y: Conducts current to the armature and reverses direction of current

Explanation:

Carbon brush is a motor brush that acts as the conducting block for current between the stator and the rotor of a motor.It is made of carbon blocks.The brush is held in place using a spring that ensures its contact position with the commutator.The commutator prevents the torque on the motor from reversing whenever the coil is rotating in the magnetic field.

5 0

3 years ago

Read 2 more answers

Two sound waves, from two different sources with the same frequency of 420 Hz travel in the same direction at 336 m/s. The sourc

Tresset [83]

Answer:

Pi(3.14) radians or 180º degrees

Explanation:

First of all, we need to obtain the wavelength of a wave traveling to the speed of sound and 420 Hz of frequency.

The formula is:

$l=wavevelocity/frequency$

where l = wavelength in meters

With current values:

l = 336 [m/s]/420[1/s] = 0.8 meters

Since a complete cycle (360º or 2pi radians) needs 0.8 meters to complete, 0.4 meters or 40 cm is just half of it, making a 180º degree phase or 3.14 radians.

8 0

3 years ago

A bird sitting high in a tree is an example of an object with what type of energy?

Wewaii [24]

<span>potential energy because it has the ability to do work

*A*</span>

7 0

3 years ago

Read 2 more answers