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?

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?