A 10-cm-long thin glass rod uniformly charged to 11.0 nC and a 10-cm-long thin plastic rod uniformly charged to - 11.0 nC are placed side by side, 4.10 cm apart. What are the electric field strengths E1 to E3 at distances 1.0 cm, 2.0 cm, and 3.0 cm from the glass rod along the line connecting the midpoints of the two rods?

Respuesta :

Answer:

[tex]E_1=3.3\times10^5\ \rm N/C\\E_2=1.9\times10^5\ \rm N/C\\E_3=2.4\times10^5\ \rm N/C\\[/tex]

Explanation:

Given:

  • Length of the rod, L=10 cm
  • Magnitude of the charge on the rods Q=11 nC
  • The distance between the rods d=4.10 cm

We know that the Electric Field due to the rod at the distance r on the axis along the perpendicular bisector of the rod is given by

[tex]E=\dfrac{2k\lambda}{r}[/tex]

At r= 1 cm from the glass rod

So we have [tex]E_1=2k\lambda \left (\dfrac{1}{0.01}-\dfrac{1}{0.031} \right)\\\\E_1=2\times 9\times10^9 \dfrac{11\times10^{-9}}{0.1} \left (\dfrac{1}{0.01}-\dfrac{1}{0.031} \right)\\\\E_1=3.3\times10^5\ \rm N/C[/tex]

The electric Field will be in the direction of plastic rod from glass rod.

At r= 2 cm from the glass rod

So we have [tex]E_2=2k\lambda \left (\dfrac{1}{0.02}+\dfrac{1}{0.0321} \right)\\\\E_2=2\times 9\times10^9 \dfrac{11\times10^{-9}}{0.1} \left (\dfrac{1}{0.02}+\dfrac{1}{0.021} \right)\\\\E_2=1.9\times10^5\ \rm N/C[/tex]

The electric Field will be in the direction of plastic rod from glass rod.

At r= 3 cm from the glass rod

So we have [tex]E_3=2k\lambda \left (\dfrac{1}{0.03}+\dfrac{1}{0.011} \right)\\\\E_3=2\times 9\times10^9 \dfrac{11\times10^{-9}}{0.1} \left (\dfrac{1}{0.03}+\dfrac{1}{0.011} \right)\\\\E_1=2.4\times10^5\ \rm N/C[/tex]

The electric Field will be in the direction of plastic rod from glass rod.