Worksheet: OR Gates

In this worksheet, we will practice determining the input and output of OR gates in logic circuits and completing truth tables for OR gates.

Q1:

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

  • A(b)
  • B(d)
  • C(c)
  • D(a)

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 𝑝
1 0 1
1 1 𝑞

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

What is the value of 𝑝 in the table?

What is the value of 𝑞 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?

Q7:

Input 𝐴 Input 𝐵 Input 𝐶 Output
0 0 0 0
0 0 𝑝 1
0 1 0 1
0 1 1 𝑞
𝑟 0 0 1
1 0 1 1
1 1 0 𝑠
1 1 1 1

The diagram shows two OR gates connected as part of a logic circuit. The truth table shows the output for the various combinations of inputs.

What is the value of 𝑝 in the table?

What is the value of 𝑞 in the table?

What is the value of 𝑟 in the table?

What is the value of 𝑠 in the table?

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.