State the function of a comparator circuit that includes an operational amplifier (op-amp).
On Fig. 10.1, draw a circle around the section of the circuit that is acting as the output device.
Show that the potential at the non-inverting input of the op-amp is $1.0\,\text{V}$.
On the axes of Fig. 10.2, draw how the output potential of the op-amp varies with time $t$.
State whether each diode is emitting light or not emitting light at time $t_1$ and at time $t_2$. At time $t_1$, diode R will __________ and diode G will __________. At time $t_2$, diode R will __________ and diode G will __________.
On the axes of Fig. 10.2, draw the way the output potential of the op-amp changes with time $t$.
State whether each diode is emitting light or not emitting light at time $t_1$ and at time $t_2$. At time $t_1$, diode R will ________ and diode G will ________. At time $t_2$, diode R will ________ and diode G will ________.