162367 Give the sign of the work done by the field in moving a small positive charge from $Q$ to $P$.

162368 Determine the electrostatic potential energy of a system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ (and with no external field) placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively.

162372 Suppose that the same system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively is placed in an external electric field $E=A\left(1/r^2\right);A=9\times {10}^5{\mathrm{NC}}^{-1}{\mathrm{m}}^2$. What would the electrostatic energy of the configuration be?

162367 Give the sign of the work done by the field in moving a small positive charge from $Q$ to $P$.

162368 Determine the electrostatic potential energy of a system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ (and with no external field) placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively.

162370 Assertion : Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting.
Reason : To enable them to conduct charge (produced by friction) to the ground; as too much of static electricity accumulated may result in spark and result in fire.

162372 Suppose that the same system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively is placed in an external electric field $E=A\left(1/r^2\right);A=9\times {10}^5{\mathrm{NC}}^{-1}{\mathrm{m}}^2$. What would the electrostatic energy of the configuration be?

162367 Give the sign of the work done by the field in moving a small positive charge from $Q$ to $P$.

162368 Determine the electrostatic potential energy of a system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ (and with no external field) placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively.

162370 Assertion : Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting.
Reason : To enable them to conduct charge (produced by friction) to the ground; as too much of static electricity accumulated may result in spark and result in fire.

162372 Suppose that the same system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively is placed in an external electric field $E=A\left(1/r^2\right);A=9\times {10}^5{\mathrm{NC}}^{-1}{\mathrm{m}}^2$. What would the electrostatic energy of the configuration be?

162367 Give the sign of the work done by the field in moving a small positive charge from $Q$ to $P$.

162368 Determine the electrostatic potential energy of a system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ (and with no external field) placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively.

162370 Assertion : Ordinary rubber is an insulator. But special rubber tyres of aircraft are made slightly conducting.
Reason : To enable them to conduct charge (produced by friction) to the ground; as too much of static electricity accumulated may result in spark and result in fire.

162372 Suppose that the same system consisting of two charges $7\mu \mathrm{C}$ and $-2\mu \mathrm{C}$ placed at $(-9\mathrm{cm},0,0)$ and $(9\mathrm{cm},0,0)$ respectively is placed in an external electric field $E=A\left(1/r^2\right);A=9\times {10}^5{\mathrm{NC}}^{-1}{\mathrm{m}}^2$. What would the electrostatic energy of the configuration be?