2-Input OR Gate



To study and verify the truth table of 2-Input OR Gate.

Learning Objectives

  1. To understand the behavior and demonstrate the operation of 2-Input OR Gate.
  2. To apply knowledge of the fundamental gates to create truth tables.
  3. To develop digital circuit building and troubleshooting skills.
  4. To understand key elements of TTL logic specification or datasheets.

IC Used

For 2-Input OR Gate:
IC NumberIC Name
74LS32Quad 2-input OR Gates

Circuit Tutorials:


  1. Place the IC on IC Trainer Kit.
  2. Connect VCC and ground to respective pins of IC Trainer Kit.
  3. Implement the circuit as shown in the circuit diagram.
  4. Connect the inputs to the input switches provided in the IC Trainer Kit.
  5. Connect the outputs to the switches of O/P LEDs
  6. Apply various combinations of inputs according to the truth table and observe the condition of LEDs.
  7. Note down the corresponding output readings for various combinations of inputs.
  8. Power Off Trainer Kit, disconnect all the wire connections and remove IC's from IC-Base.


OR GATE - ​ It is a digital circuit that has two or more inputs and produces an output,which is the logical OR of all those inputs. This logical OR is represented with the symbol ‘+’

Logic OR Gates are available using digital circuits to produce the desired logical function and is given a symbol whose shape represents the logical operation of the OR gate. Like the AND gate, the OR function can have any number of individual inputs. However, commercial available OR gates are available in 2, 3, or 4 inputs types. Additional inputs will require gates to be cascaded together to obtain the required output value

Boolean Expression Y = A+B

"If either A or B is true, then Y is true"

This OR gate produces an output Y, which is the logical OR of two inputs A, B.

Block Diagram


  1. Make the connections according to the IC pin diagram.
  2. The connections should be tight on trainer kit.
  3. The Vcc and ground should be applied carefully at the specified pin only.


We have learned the 2-Input OR Gate IC according to the IC pin diagram.