# All Questions

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### How do I calculate the total resistance of this circuit? [on hold]

How do I calculate the total resistance of this circuit? From the data from a site it can be calculated that the total resistance is $\frac{12\ V}{5.14\ A}$ which is $2.33\space \Omega$. But I don't ...
12 views

### Calculate the power supplied by voltage source [on hold]

Hi for this question (sorry about the picture), if the current source ($2A$) receives $20 W$ of Power, determine the $R$ of the resistor and the power of the voltage source. I sort of know I have to ...
18 views

### Find effective resistance between x and y [closed]

Find equvalent resistance between x and y
58 views

### If the speed of electron (in space) is increased, will the magnitude of current also increase? [closed]

Electrons are emitted by a hot filament and are accelerated by an electric field, as shown in the figure. The two stops at the left ensure that the electron beam has a uniform cross-section. (a) ...
146 views

### Magnetic field in a capacitor

If in a flat capacitor, formed by two circular armatures of radius $R$, placed at a distance $d$, where $R$ and $d$ are expressed in metres (m), a variable potential difference is applied to the ...
31 views

### Does the potential difference between two points remain the same if there spatial location is changed?

I was working through this particular homework problem. Where I am required to find out the current flowing through the resistor A (4 ohms). First of all I saw that the 2 resistors were in parallel ...
107 views

### Induced Currents in Circuits

I was given the following question:- The plane figures shown are located in a uniform magnetic field directed away from the reader and diminishing. The direction of current induced in the loops is ...
52 views

### Determining current in a branch having no resistor [closed]

In context to the diagram below , it is quite easy to find the current flowing through section AD , which turns out to be 2A , however , I cannot determine the current in any other branches with ...
35 views

I was looking at past exam papers and found a question that I can't understand. It is basically about current flow but the diagram is really confusing me. The diagram is the following: The question ...
51 views

### Divergence of current density and electric field within a wire

In the following exercise: I concern myself with the validity of my interpretations of (b). Here I am more confident slightly. The divergence of the current density is merely $- d \rho / dt$, so as ...
22 views

### Formula for total current and phase angle in function of given currents and phase angles in the branches of a parallel RLC circuit

Consider this parallel RLC circuit powered by an sinusoidal alternating voltage and two branches, one containing an ohmic resistance $R_1$ and a capacity $C$, the other one containing an ohmic ...
57 views

### Orientation of resistor when connected in a cicuit [closed]

Consider a cuboid shaped resistor. Now Case1: Connect the resistor along is length to a battery. Case2: Connect the resistor along is breadth to a battery. In the two cases the length and cross-...
126 views

### What remains the same: voltage, current or resistance? [closed]

A current 1 ampere passed through a conductor which resistance is 10 ohms, if the current become 2 amperes, then will the resistance of the conductor will remain 10 ohms, and if not, then what is the ...
38 views

### Potential in open branch of a parallel circuit with grounding [closed]

If the switch is still open, what will the electric potential at Q be, i.e. negative, positive or zero? Is there a potential difference across the grounded point and point Q, or R3, even though the ...
139 views

### Is internal resistance of cell part of the equivalent resistance of the network of resistors?

Do we include the internal resistance of cell while calculating equivalent resistance of network? Take, for instance, the question given. Do we include the 1 ohm internal resistance while calculating ...
66 views

### Why in a DC series Circuit do bulb attached in parallel to highest resistance glow brightest? [closed]

I was performing an experiment in which there were five resistances connected in series and then I connected a bulb with each of the resistance. Each bulb was connected in parallel to each resistance ...
77 views

### Brightness of lamp

Brightness of lamp (power) depends on two factors: Current which flows through the lamp. voltage (p.d) across the lamp. In the figure: When the variable resistance increases, what happens to the ...
62 views

### Calculate the voltage between terminals a and b [closed]

Calculate the voltage between terminals a and b before and after connecting the external resistance R, then calculate absolute and relative difference of these voltages.
409 views

### What is the equivalent resistance between $A$ and $B$ in the given circuit? [closed]

Hi, I've been doing some current electricity problems by using Kirchhoff's laws. I've tried applying KVL(Kirchhoff Voltage law) to this circuit, but to no avail. There happens to be too many variables ...
97 views

### Can electric potential be discontinuous?

I am studying the following problem, which is 9.11 of "Modern Electrodynamics" by Zangwill. The idea is that you have a wire attached to a perfectly conducting sphere (radius $a$) buried into the ...
707 views

### Hardest circuit diagram

I have provided an example of the type of problem I am having issues with. In the given diagram, the resistances and batteries are identical and the batteries do not have internal resistances(for the ...
39 views

### Compare the time the power sources in these circuits will last

I am trying to conceptualize the time which a battery will last in a given circuit. Below is an example from which I will explain the questions which I am struggling with : Lets begin by asking this ...
55 views

### Circuit Diagram Problem [closed]

I solved a problem in which I was supposed to find the current over the ammeter. The answer is 12 because the total voltage over the circuit is given as 128 V. However, I do not understand why we don'...
274 views

### How to determine direction of the current in the following circuit? [closed]

What would be the direction of the current on R3? Can there be current moving in both directions?(left and right?)
26 views

### Integrating Ampère's force law to find the force between wires [closed]

I want to find the force between parallel current carrying wires using Ampère's force law. Ampère's force law is given as \begin{align} dF&= \frac{\mu}{4\pi} \frac{I_1dL_2\times(I_2dL_2\times r_{...
97 views

### Simple electronic circuit analysis [closed]

I have to find a substitute for this circuit. (The substitution is on the right) The arrows in one circle are perfect voltage sources. The arrows in two circles are perfect current sources. It ...
53 views

### circuit analysis [closed]

I have been struggling with this circuit below since my teacher asked a question about it. The question is: -Is there any current flowing in the wire in the middle? The answer is yes. I tried to ...
261 views

### This question was on my physics test (about basic DC circuits) [closed]

So in the following question: Because the wire has a resistance of near 0, is there no current going through the resistor with the arrow pointing at it. I understand that normally both resistors in ...
60 views

### Dependency of temperature acquired by a resistor on power

A nichrome heating element across 230V supply consumes 1.5kW of power and heats up to 750*C. A tungsten bulb across the same supply operates at a much higher temperature of 1600*C in order to emit ...
44 views

1k views

### Charge flowing through switch when it is closed [closed]

The problem that I'm having is that the initial charges would have been 300 and 600 microcoulomb on the 3 and 6 microfarad capacitors respectively. But when the switch is closed there's some charge ...
455 views

### Why doesn't a bird on an electric line get electrocuted? KVPY 2017 [duplicate]

A bird sitting on a single high tension wire does not get electrocuted because A) the circuit is not complete B) the bird feet has an insulating covering. C) capacitance of the bird is ...