A Level Physics OCR Electricity Questions and Answers

Electrical Current Rate of flow of charge; Movement of electrons in metals; Movement of ions in electrolytes. Measured in amperes. I = Q/t. I = Anev. Conventional current: + to -. Flow of electrons: - to +. Electrical Charge A fundamental property of certain particles that causes them to experience a force in the presence of electric fields. Measure in coloumbs. 1 coloumb is the amount of charge that passes in 1 second when the current is 1 ampere. Charge of electrons is - elementary charge. e = 1.6x10⁻¹⁹C. Net charge on matter is always a multiple of e; charge is quantised. coulomb The amount of charge that passes through a point in one second when the current is 1 amp. smallest unit of charge change on an electron Kirchhoff's First Law Sum of current entering a junction is equal to the sum of current leaving the junction.