A microfluidic channel has a steady current of 4.8 μA4.8\,\mu\text{A}4.8μA flowing through it due to the movement of magnesium ions (Mg2+\text{Mg}^{2+}Mg2+). The ions are driven by a uniform electric field.
Which row in the table correctly identifies the direction of the electrostatic force on these ions relative to the electric field lines and the number of ions passing a cross-section of the channel per minute?
| Direction of force on the Mg2+\text{Mg}^{2+}Mg2+ ions | Number of ions passing a cross-section per minute | |
|---|---|---|
| A | Opposite to the electric field lines | 1.8 × 1015 |
| B | In the same direction as the electric field lines | 9.0 × 1014 |
| C | Opposite to the electric field lines | 9.0 × 1014 |
| D | In the same direction as the electric field lines | 1.8 × 1015 |
Row A
Row B
Row C
Row D
15 exam-style questions on OCR GCSE Physics Static and charge. Each one has a worked solution and a mark scheme showing where the marks go.