Worked example The switch in the following circuit is closed at time = 0. t (a) Immediately after closing the switch what is (i) the charge on the capacitor? (ii) the pd across the capacitor? (iii) the pd across the resistor? (iv) the current through the resistor? (b) When the capacitor is fully charged what is (i) the pd across the capacitor? (ii) the charge stored on the capacitor? Solution: (a) (i) The initial charge on the capacitor is zero. The initial pd across the capacitor is zero since there is no charge. pd across the resistor is 10 V (VR = VS VC = 10 0 = 10 V) – – (iv) 1 × 10–5 A (b) (i) Final pd across the capacitor equals the supply voltage, 10 V. (ii) Q = VC = 2 × 10–6 × 10 = 2 × 10–5 C 3.2 Electrons at Work Conductors, Semi conductors and Insulators
Worked example The switch in the following circuit is closed at time t = 0. (a) Immediately after closing the switch what is (i) the charge on the capacitor? (ii) the pd across the capacitor? (iii) the pd across the resistor? (iv) the current through the resistor? (b) When the capacitor is fully charged what is (i) the pd across the capacitor? (ii) the charge stored on the capacitor? Solution: (a) (i) The initial charge on the capacitor is zero. The initial pd across the capacitor is zero since there is no charge. pd across the resistor is 10 V (VR = VS – VC = 10 – 0 = 10 V) (iv) 1 × 10–5 A (b) (i) Final pd across the capacitor equals the supply voltage, 10 V. (ii) Q = VC = 2 × 10–6 × 10 = 2 × 10–5 C 3.2 Electrons at Work Conductors, Semi conductors and Insulators
sasbhs_science_physics_highers_12_3051020589.docx