0
votes
2answers
41 views

Electric power transmission

If we want to transmit electic current for a long distance, we must minimize a heat that releases because of the resistanse. We cannot make a cable wide because it is expensive and it will be massive. ...
0
votes
0answers
39 views

Magnetic field at a point [closed]

Find the magnetic field near a straight current carrying conductor of Length $L$ and current $I$, at point located along the perpendicular bisector of the wire a distance $r$ from the wire. Show all ...
0
votes
1answer
60 views

how to find the diameter of this fuse? [closed]

A fuse blows if the current exceeds 1.0 A. It is made of material that melts at a current density of 620A/cm2. What is the diameter of the wire, assumed to have a circular profile, in the fuse?
1
vote
5answers
550 views

Parallel circuits - Overall resistance decreases with additional resistor

Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
0
votes
1answer
461 views

Relationship between resistance and voltage drop

In a series or parallel circuit, if two bulbs have the same resistance, do they have the same voltage drops? The problem I am asking about is below. Do A, B, and C have the same voltage drops since ...
0
votes
0answers
142 views

RMS value of the A.C. current? [closed]

What is the RMS value of current $i=3+4sin(\omega t+\pi/3)$? Please give step by step solution.
0
votes
3answers
291 views

charge density in a wire

if we have a infinitely thin and infinitely long straight wire on the z-Axis with given current I(t), how can i compute the charge density? I figured out that the current-density is given by ...
0
votes
1answer
152 views

How do I solve the current of this resistor using Maxwell's Current Theorem?

I've been trying to solve this using the method the prof. taught us, and I happen to know the answer but I can't reach it no matter how many times I've tried. The circuit in question is below: I am ...
0
votes
1answer
332 views

Calculate the UPS Capacity in amp-hours [closed]

I am trying to find out the UPS capacity in amp-hours for my HP UPS system. I've already done some calculations based on the UPS information from the HP Power Manager software. Bellow are my ...
1
vote
3answers
2k views

Finding current using EMF & internal resistance

What exactly is the difference between internal resistance and resistance? This came up in the context of a homework problem I have been given: The circuit shown in the figure contains two ...
0
votes
1answer
175 views

Capacitance and Light Bulb And Dielectric Slab [closed]

An electric lamp having coil of negligible inductance connected in series with a capacitor and an AC source is glowing with certain brightness. How does the brightness of the lamp change on reducing ...
0
votes
0answers
139 views

How much current needed to cancel Earth's magnetic field [closed]

It can be shown the magnetic field in a long narrow tube that is 5 meters is uniform and given by $$B=1.26 \times 10^{-6} N I$$ where N is number of wire loops/meter. Assuming the solenoid is aligned ...