Recent content by Conductivity

After we proved Y-Δ transform using superposition theorem, The professor asked us what would happen if you have a Y circuit but a resistor is connected to the middle node. Can you do the transformation? She answered and said yes, and that resistor will be connected to nothing. How can that be...

Homework Statement The problem states: 2 concentric shells made out of conductive materials as in the diagram. R2/ R1 = 6. If the shells were charged with a total charge of 100 nc the connected with a wire, Then the final charge on both shells would be? 1) 33.3, 66.7 2) 30, 70 3) 20, 80 4)...

In the derivation of the electric field inside a non conducting sphere, We still use the permittivity of free space even though we are in a medium. The same applies for ampere's law in a solid wire. http://physics.bu.edu/~duffy/semester2/c15_inside.html...

Don't we idealize a solenoid as a number of circular coils? https://i.imgur.com/RCO3qcQ.png If we take a dx piece of this solenoid and treat at as k number of coils, The equation for a single coil is: ## B = \frac{ u_o i R^2}{2 ( R^2 + x^2)^{\frac{3}{2}}} ## If dx has 2 turns then we...

Hello, I have seen that biot savart's law works for infinitely narrow wires: "The formulations given above work well when the current can be approximated as running through an infinitely-narrow wire." When I wanted to derive the magnetic field of a solenoid, I had to do this substitution...

Thank you both, Thank you truly.

I re-read everything a couple of times, understood each point and the infinitesimal argument. Just this last point because it wasn't discussed, If we define a surface element to be as ##\lim_{n \rightarrow +\infty} {\frac {A_t} n} ## ( I defined it as that so we can have the same infinitesimal...

Ah, I don't think infinitesimal as small finite number but as something that neither is zero nor finite something that can be expressed with a symbol like dx which has properties we want. I didn't understand some bits, But I will re-read all your posts again and try to understand where I went...

Thank you for replying I meant dot product sorry. Wouldn't the area be an infinitesimal area around the point of intersection? assuming I take it around every point which is the integral? So it is all the same. What is wrong with this please?

Let me just say what I know about magnetic field lines so we can be on the same page: 1) tangent to the direction. 2) represents the strength of magnetic field, further apart represents low magnetic field and the opposite. and some other properties but not important here I have always thought...

We took today in a lecture gauss' law for magnetism which states that the net magnetic flux though a closed shape is always zero (Monopoles don't exist). The professor explained/proved it as following (Since it needs math theorems): Draw any shape. From the fact that any magnetic field line that...

In force-couple system equivalence, We can show that two systems are equivalent if the resultant force in both are equal and that it has the same line of action. So Rx1 = Rx2, Ry1= Ry2, Ma1 = Ma2 Now my book says we can use another form of equation: We can choose 3 point and find the moment...

in the ideal fluid situation yes, hydrostatic pressure a bit far from the exit hole then pressure decreases as we reach the exit hole so that it becomes atmospheric. However, In the viscous fluid problem I assumed that the pressure at the exit hole( the opening of the pipe in the tank) is...

Viscosity example: we have Q = pi delta P a^4/(8 n L) we have everything except delta P, Which we will use to find h1 and h2 For h1, Delta P = rho g (0.4) - rho g h1 Of course this is under the assumption that v of the fluid in tank is zero. Doesnt this assumption cause a velocity...

Homework Statement In the given picture, A cylindrical tank has a viscous fluid with density 800 kg/m^3 and viscosity of 0.8 Pa.s. A small pipe is attached to the tank with a cross sectional area of 1 cm^2. If Q = 3.12 x 10^-6 m^3/s, Find h1, h2 ,x Homework Equations Q = pi delta P a^4/(8 n...