Answer:
1.35 A
Explanation:
Applying,
V = IR
I = V/R..................... Equation 1
I = Current, V = Voltage, R = Resistance.
But,
R = Lρ/A............... Equation 2
Where L = Length of the wire, ρ = resistivity, A = Cross-sectional area of the wire.
Sustitute equation 2 into equation 1
V = AV/Lρ............... Equation 3
From the question,
Given: V = 0.7 V, A = 0.290 mm² = 2.9×10⁻⁷ m², L = 1.5 m, ρ = 10×10⁻⁸ Ω.m
Substitute these values into equation 3
I = (0.7× 2.9×10⁻⁷)/(1.5× 10×10⁻⁸ )
I = (2.03×10⁻⁷)/(15×10⁻⁸)
I = 1.35 A
Answer:
C
What is the answer please help her
The difference between the maximum and minimum values of voltage V across the 3 ohm resistor would be 9V.
To find the minimum and maximum values of V across the 3 ohm resistor, you will need to use Ohm’s Law, V=IR.
You already know the resistance is 3 ohms across the resistor; in order to calculate the maximum/minimum voltage across it, you will need to work out the maximum/minimum current of the series circuit.
Using Ohm’s Law to find the maximum and minimum current:
I = V/R
Where:
V = 12V (this is the emf, no volts are lost to the cell because the cell has a negligible internal resistance therefore all the 12V is transferred to the resistors in the circuit.)
The value for R however, changes due to the resistance in the variable resistor varying from 0 to 9 ohms.
The minimum value of R would be 3 ohms, where the resistance of the variable resistor is 0. Therefore total resistance = 3 + 0 = 3 ohms
Maximum value of R would be 12 ohms, where the resistance of the variable resistor is at a maximum of 9 ohms. Therefore total resistance = 3 + 9 = 12 ohms
The rest of the explanation is in the picture, hope it makes sense
Answer:
1.5min
Explanation:
To solve the problem it is necessary to take into account the concepts related to Period and Centripetal Acceleration.
By definition centripetal acceleration is given by
![a_c = \frac{V^2}{r}](https://tex.z-dn.net/?f=a_c%20%3D%20%5Cfrac%7BV%5E2%7D%7Br%7D)
Where,
V = Tangencial velocity
r = radius
With our values we know that
![a_c = \frac{V^2}{r}](https://tex.z-dn.net/?f=a_c%20%3D%20%5Cfrac%7BV%5E2%7D%7Br%7D)
![\frac{V^2}{r} = \frac{1}{10}g](https://tex.z-dn.net/?f=%5Cfrac%7BV%5E2%7D%7Br%7D%20%3D%20%5Cfrac%7B1%7D%7B10%7Dg)
Therefore solving to find V, we have:
![V = \sqrt{\frac{1}{10}g*r}](https://tex.z-dn.net/?f=V%20%3D%20%5Csqrt%7B%5Cfrac%7B1%7D%7B10%7Dg%2Ar%7D)
![V = \sqrt{\frac{9.81*200}{10}}](https://tex.z-dn.net/?f=V%20%3D%20%5Csqrt%7B%5Cfrac%7B9.81%2A200%7D%7B10%7D%7D)
![V = 14m/s](https://tex.z-dn.net/?f=V%20%3D%2014m%2Fs)
For definition we know that the Time to complete are revolution is given by
![t = \frac{Perimeter}{Speed}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7BPerimeter%7D%7BSpeed%7D)
![t = \frac{2\pi R}{V}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B2%5Cpi%20R%7D%7BV%7D)
![t = \frac{2\pi * 200}{14}](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7B2%5Cpi%20%2A%20200%7D%7B14%7D)
![t = 1.5min](https://tex.z-dn.net/?f=t%20%3D%201.5min)