Which is the best description of r.m.s. voltage?
An average of the voltage over one cycle
The maximum voltage over one cycle
The effective voltage equivalent to d.c. voltage
An alternating current signal is displayed on an oscilloscope as shown in the diagram:
Use the information to determine the peak voltage.
\[5 V\]
\[10V\]
\[20 V\]
Use the information to determine the period of the signal.
\[0.06 s\]
\[0.12 s\]
\[120s\]
Use the information to determine the frequency.
\[16.7 Hz\]
\[8.33Hz\]
\[0.00833Hz\]
If the trace was replaced by a signal of higher frequency but same peak voltage, describe what would be seen on the screen.
More cycles with peaks of the same height closer together
Fewer peaks of the same height further apart
The same number of peaks but higher at the top and lower at the troughs
A heater element has resistance of \(26 \Omega\). It is connected to the mains which has an r.m.s. voltage of \(230 V\). Calculate the peak voltage of the mains.
\[162 V\]
\[325 V\]
\[460V\]
A heater element has resistance of \(26 \Omega\). It is connected to the mains which has an r.m.s. voltage of \(230V\). Calculate the r.m.s. current in the heater.
\[8.85 A\]
\[12.5A\]
\[0.113 A\]
A heater element has resistance of \(26 \Omega\). It is connected to the mains which has an r.m.s. voltage of \(230V\). Calculate the peak current.
\[8.846 A\]
\[6.26 A\]
A heater element has resistance of \(26 \Omega\). It is connected to the mains which has an r.m.s. voltage of \(230V\). Calculate the effective (r.m.s.) power.
\[2030 W\]
\[2870W\]
\[4070W\]
A heater element has resistance of \(26 \Omega\). It is connected to the mains which has an r.m.s. voltage of \(230V\). Calculate the maximum (peak) power.
\[2030W\]