1. | \(\dfrac{1}{r^2}\) | 2. | \(\dfrac{1}{r}\) |
3. | \(r\) | 4. | \(\dfrac{1}{r^3}\) |
1. | \(q,Q\) are of the same sign and \(|q|=|Q|\) |
2. | \(q,Q\) are of opposite signs and \(|q|=|Q|\) |
3. | \(q,Q\) are of the same sign and \(|q|<|Q|\) |
4. | \(q,Q\) are of opposite signs and \(|q|>|Q|\) |
1. | \(|\vec E_m|=\left|\dfrac{\vec E_Q}{K}\right|,\) and the two fields are in opposite directions. |
2. | \(|\vec E_Q|=\left|\dfrac{\vec E_m}{K}\right|,\) and the two fields are in the same direction. |
3. | \(|\vec E_Q+\vec E_m|=\left|\dfrac{\vec E_Q}{K}\right|,\) and the two fields are in opposite directions. |
4. | \(|\vec E_Q+\vec E_m|=\left|\dfrac{\vec E_m}{K}\right|,\) and the two fields are in the same direction. |
1. | I, III | 2. | II |
3. | I, II, III | 4. | none of I, II, III |
1. | \(\dfrac{2}{9}\) | 2. | \(\dfrac{4}{9}\) |
3. | \(\dfrac{9}{2}\) | 4. | \(\dfrac{9}{4}\) |
1. | zero |
2. | towards the centre |
3. | away from the centre |
4. | either towards or away from the centre depending on the sign of \(q\) |