 # Electric current problems with answers

Recent questions in Electric current linziboobeary1o8p 2022-05-18

### A charge of 36C passes through a circuit every 9s. If the circuit can generate 32W of power, what is the circuit's resistance? Brody Collins 2022-05-18

### How much power is produced if a voltage of 2V is applied to a circuit with a resistance of $10\mathrm{\Omega }$? pevljivuaosyc 2022-05-18

### Say we got an alloy made of $90$% Au and 10%Cu. The atomic mass of gold is${A}_{Au}=197g/mole$and of copper${A}_{Cu}=63.5g/mole$The specific resistivity of gold is$\rho =22.8n\mathrm{\Omega }m$and the Nordheim coefficient is$C=450n\mathrm{\Omega }m$Then by the Nordheim rule we have that the resistivity of this alloy is given as$\rho ={\rho }_{Au}+CX\left(1-X\right)$where X=0.1, and represents the percentage of Copper in the alloy. Using the above I got that$\rho =63.3n\mathrm{\Omega }m$, but data shows that the actual resistivity is $\rho =108n\mathrm{\Omega }m$. What about X? Is it the percentage of atoms in the alloy, or is it the percentage of mass in the alloy? Jordon Haley 2022-05-18

### If $a,b,c\in \left(0,\mathrm{\infty }\right)$ with abc=1 prove:${a}^{2}+{b}^{2}+{c}^{2}+3\left(ab+bc+ca\right)\le \frac{1}{2}\left(\sqrt{a}+\sqrt{b}+\sqrt{c}\right)\left(a+b\right)\left(b+c\right)\left(c+a\right).$On atypical inequality (a smaller amount than a product) that resisted my attempts to prove it. Marco Villanueva 2022-05-17

### What is the resistivity coefficient of graphene? quorums15lep 2022-05-17

### The Hall coefficient is defined as this:${R}_{H}=\frac{{E}_{y}}{{j}_{x}{B}_{z}}.$Always as ${R}_{H}$. I am currious as to how to use this coefficient? Is it the y-direction resistance/resistivity (it is very close to the general resistivity from Ohm's law $\rho =E/j$)? Then I should be able to find it by ${R}_{H}={V}_{y}/{I}_{y}$ (or ${R}_{H}={E}_{y}/{j}_{y}$).or is it simply defined as this as a proportionality constant (it does indeed look good with the three factors combined around one constant) and not an actual physical quantity? Brooklynn Hubbard 2022-05-17

### What is the electric current produced when a voltage of 15V is applied to a circuit with a resistance of $6\mathrm{\Omega }$ ? agrejas0hxpx 2022-05-15

### Derivative of ${e}^{-x}$ Daphne Haney 2022-05-15

### A Binomial Coefficient Sum: $\sum _{m=0}^{n}\left(-1{\right)}^{n-m}\left(\genfrac{}{}{0}{}{n}{m}\right)\left(\genfrac{}{}{0}{}{m-1}{l}\right)$ Regina Ewing 2022-05-15

### What is the statement of Ohm's Law? Peia6tvsr 2022-05-15

### How do you calculate voltage drop in a series circuit? Jazlyn Raymond 2022-05-15

### What would happen with the drift velocity of a cylindrical resistor's diameter increases, with a given voltage between its terminals? According to the expression:$\begin{array}{rl}R& =\rho \frac{L}{A}\\ I& =neA{v}_{d}\\ \mathrm{\Delta }V& =IR\\ {v}_{d}& =\frac{\mathrm{\Delta }V}{\rho Lne}\end{array}$The resistivity does not change, neither does the length of the resistor nor the term ne but the resistance does change as well as the current, so the area is eliminated from the expression. I wonder if the drift velocity would be the same after increasing the diameter or if my derivation is wrong. Nubydayclellaumvcd 2022-05-14

### Velocity of projectile with both quadratic and constant resistive forceSuppose we have a projectile of mass m that impacts a material with velocity ${v}_{0}$. As it travels through the material it is subject to the resistive force $F=\alpha {v}^{2}+\beta$. How can I determine $v\left(t\right)$, the velocity of the projectile at time t where t=0 is the impact time, and $v\left(p\right)$, the velocity of the projectile when it reaches a penetration depth of p?This question addresses v(t) for an exclusively quadratic resistive force ($\beta =0$), but is there a more general formula for when there is a constant component? Yasmine Larson 2022-05-14

### Resistivity in terms of temperature coefficient of resistance$R={R}_{0}\ast \left(1+\alpha \left(T-{T}_{0}\right)\right)$Where ${R}_{0}$ and ${T}_{0}$ are the reference resistance and temperature.Is it then safe to say that:$\rho ={\rho }_{0}\ast \left(1+\alpha \left(T-{T}_{0}\right)\right)$(where ${\rho }_{0}$ is the reference resistivity)? Blaine Stein 2022-05-14

### How to prove ${\int }_{0}^{1}\frac{1+{x}^{30}}{1+{x}^{60}}dx=1+\frac{c}{31}$, where 0 syaoronsangelhwc17 2022-05-14

### What is the minimal polynomial of $\alpha =\frac{{3}^{1/2}}{1+{2}^{1/3}}$ over $\mathbb{Q}$? vilitatelp014 2022-05-14

### Is the resistivity of all (conducting) alloys more than that of all (conducting) metals? Osmarq5ltp 2022-05-14

### The wires in (Figure 1) all have the same resistance; the length and radius of each wire are noted.Rank in order, from largest to smallest, the resistivities ${\rho }_{1}$ to ${\rho }_{5}$ of these wires. Logan Lamb 2022-05-13
### I know what resistivity of materials are like, and is given by the formula:$R=\frac{\rho L}{A}$However what is the volume resistivity of materials like copper and aluminium for instance? How do we calculate the volume resistivity of materials, because this was confusing when I read the site:Method of calculating eddy currents of a conductor, is this correct?Where there is the answer given by Floris states the equation:$F=\frac{v\cdot {B}^{2}\cdot A}{\rho /t}$Where $\rho$ is given to be the volume resisitivity.My question:how do we measure the volume resistivity of a material for example aluminium?what happens if the thickness of the material changes? lurtzslikgtgjd 2022-05-13