$1.$ a$)$ Design a led circuit.

i$)$ state the forward bias current of your diode

ii$)$ using a $5$V voltage source, determine a suitable resistor

iii$)$ show a schematic of your circuit

b$)$ Show a picture of your virtual circuit

$2.$ a$)$ Draw the schematic for the digital logic circuit with led indicator. $[2]$

b$)$ Show a picture of your virtual circuit

c$)$ Explain why we get a digital logic output of $1$ when the switch is off and an output of $0$ when the switch is on$.$

$3.$ a$)$ Draw the schematic for the AND gate with led indicator at the output and digital logic circuits at the input.

b$)$ Show a picture of your virtual circuit

c$)$ Explain how the output is $0$ when the digital logic at one input is $1$ and the digital logic at the other input is $0.$