The standard domestic mains electricity supply in the UK is an alternating current (a.c.) supply. Which of the following pairs correctly identifies the peak voltage (VpeakV_{\text{peak}}Vpeak) and the time period (TTT) of this supply?
Vpeak≈230 VV_{\text{peak}} \approx 230\text{ V}Vpeak≈230 V, T=20 msT = 20\text{ ms}T=20 ms
Vpeak≈325 VV_{\text{peak}} \approx 325\text{ V}Vpeak≈325 V, T=20 msT = 20\text{ ms}T=20 ms
Vpeak≈325 VV_{\text{peak}} \approx 325\text{ V}Vpeak≈325 V, T=16.7 msT = 16.7\text{ ms}T=16.7 ms
Vpeak≈170 VV_{\text{peak}} \approx 170\text{ V}Vpeak≈170 V, T=16.7 msT = 16.7\text{ ms}T=16.7 ms