An alternating voltage $V$ changes with time $t$ according to $V = 18\cos(40\pi t)$, with $V$ measured in V and $t$ measured in s.
(a(i))[1]
Show that the period of the alternating voltage is $0.050\,\text{s}$.
(a(ii))[1]
Determine the root-mean-square (r.m.s.) voltage.
(b)[3]
On Fig. 7.1, sketch how $V$ varies with $t$ for values of $t$ from $t = 0$ to $t = 100\,\text{ms}$.
(c)[5]
The alternating voltage is rectified so that an output voltage appears across the load resistor $R$, as illustrated in Fig. 7.2.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Hence $T=\frac{2\pi}{40\pi}=0.050\,\text{s}$.” …
- Full mark scheme, point by point
- Step-by-step worked solution
- Write your answer & get it marked instantly by AI