**Q1: **

The diagram shows the circuit symbols for four logic gates. Which symbol represents an OR gate?

- A(b)
- B(a)
- C(c)
- D(d)

**Q2: **

The diagram shows an OR gate. If input A is 0 and the output is 0, what must input B be?

**Q3: **

OR Gate | ||
---|---|---|

Input A | Input B | Output |

0 | 0 | 0 |

0 | 1 | |

1 | 0 | 1 |

1 | 1 |

The truth table shows the output of an OR gate for various combinations of inputs.

What is the value of in the table?

What is the value of in the table?

**Q4: **

A logic circuit has 4 inputs, each of which can have a value of either 0 or 1. How many rows would you have to add to a truth table in order to show all of the different possible combinations of these inputs?

**Q5: **

The diagram shows an OR gate. If input A is 1 and input B is 0, what will the output be?

**Q6: **

The diagram shows two OR gates, where the output of the first OR gate is one of the inputs to the second. If input A is 0, input B is 0, and input C is 1, what is the output?