# Tag Info

11

Imagine a block sliding down a slope and that there is an amount of friction between the slope and the block such that the block slides down the slope at constant speed. As the block slides down the slope it loses gravitational potential energy and an equal amount of heat is generated due to the friction between the slope and block. The block does not ...

11

Question: Which of two pipes of equal length offers less resistance to the flow of water, one of which has twice the cross sectional area of the other? Answer: The one of twice the cross sectional area. But the one of twice the cross sectional area can be thought of as two of the smaller cross sectional area pipes in parallel. This analogy gives an idea of ...

10

I'm surprised that no one has yet mentioned the hydraulic analogy for electricity to help the OP understand better. A brief summary of this analogy is: Electricity is like water flowing through pipes. Current = amount of water flowing through pipe Voltage = pressure of water Power = water pressure x water flow (voltage x current) Resistors = constrictions ...

8

Suppose you have a voltage $V$ between two points A and B in a circuit. If initially you have a resistor of resistance $R_1$ between A and B, the current flowing through the resistor is $I_1=V/R_1$. Now if you connect another resistor $R_2$ in parallel to the resistor $R_1$, then the former will have the same voltage $V$ across it (since it is connected to ...

5

None of the above. Electrons are negatively charged, always. They do not become positively charged under any circumstances. In DC circuits they flow (or rather 'drift' at about 0.1 mm/s) only in one direction, from the -ve terminal to the +ve. In AC circuits they flow forwards and backwards in the wire, changing direction 50 times per second. They don't ...

5

If I have a circuit with resistance R and voltage V, I get a certain current - that's Ohm's law, $I = \frac{V}{R}$. Now imagine you have two such circuits - completely separate from each other. Each will have the same current. Let's say the voltage is 1 V, and the resistance is 1 A: Now if I connect the terminals of the two voltage sources together (...

3

It seems like you get the rational answer but lack the ability to feel it: imagine you have 5 doors of different sizes and a thousand people to pass from a to b. If all the doors are in a row (so everyone has to pass every door), it will take a lot more time compared to the situation, where you place all the doors next to each other so that every person can ...

2

Why does the current remain the same? Interesting question. As you could see from the examples with falling water or sliding blocks the gravitational potential is responsible for energy release in mechanical storage systems. For a battery this can't be the reason of energy storage. Kinetic energy inside the a battery can't be the reason too. At the end in ...

1

Have you learnt the Kirchoff current and voltage laws? Personally, I would define three loop currents, one flowing through C1, R1 from the input, one through C2 R1 from the output in the opposite direction and a loop current throuhg R2, C1, C2 as I've shown. Now write down the sum of voltages around the loops, using the complex impedance to relate the ...

1

Current is a measure of how many electrons go past a particular point in the circuit every second. So there are electrons rushing into one side of the light bulb, and rushing out of the other side. The number rushing IN each second is equal to the number rushing OUT each second. If that wasn't the case, then there'd be a build-up of electrons inside the ...

1

But if the amount of current flowing into the filament of the bulb = the amount of current flowing out of the filament and at the same time it is producing photons(light energy) [and some heat energy too] then aren't we creating energy ? Which is not possible. Current is the flow of charge over time , Q/t. It can be larger of smaller depending on the ...

1

If the amount of electrons remain the same, where does the energy come from? Batteries have energy stored inside. The energy inside a battery could accelerate electrons to a very high velocity. However, this doesn't happen in a circuit. Just as the battery speeds up an electron, the electron hits to another one and remains constant speed. So the battery ...

1

From the wording of the question I would assume the OP didn't want formulas or a very technical answer, so I'll attempt answering in layman's terms. What does resistance do? It resists the flowing of current. Given the same voltage, the bigger the resistance, the smaller amount of current can flow. Now, imagine that there is a resistor. You put another one ...

1

When you ask: So I was told in the physics class that the resistance in a parallel circuit is lesser than the resistance in a series circuit. This question only applies when two resistors are connected in series, versus the same two resistors connected in parallel instead. It's important to understand that apples-to-apples comparisons can only be made ...

1

Under the scenario you presented, all you've done is made a bigger battery. Which is just sitting there, so there is no current flow. If you open up a standard 9 volt rectangular battery you will find six 1.5 volt cells connected in series, i.e. exactly as you described.

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