Practice portal › JEE › Semiconductor Electronics

Digital Electronics and Logic Gates for JEE: 73 solved questions

Real JEE paper questions on digital electronics and logic gates, part of semiconductor electronics. Each opens with the options, the correct answer and a step-by-step solution. Papers run from 2008 to 2026. No sign-in needed to read them.

What this topic asks

• Gate combinations and truth tables — 54 questions
• Waveforms, switches and diode gates — 19 questions

All 73 questions with solutions

• If X and Y are the inputs, the given circuit works as . [Figure: X drives a NAND gate with both inputs tied t… JEE Main 2nd April 2nd Shift 2026
• Two 4-bit binary numbers, A=1101 and B=1010 are given in the inputs of a logic circuit shown in figure below.… JEE Main 4th April 1st Shift 2026
• For the given logic circuit, which of the following inputs combination will make both LED-1 and LED-2 to glow… JEE Main 5th April 1st Shift 2026
• Refer to the logic circuit given below. For two inputs (A=1,B=1) and (A=0,B=1), output (Y) will be . [Figure:… JEE Main 6th April 2nd Shift 2026
• The output Y for the given inputs A and B to the circuit is: [Figure: inputs against time. A is 0 from 0 to 1… JEE Main 8th April 2nd Shift 2026
• The given circuit works as [Figure: A feeds a NOR gate with both inputs tied; B feeds another NOR gate with b… JEE Main 21st Jan 1st Shift 2026
• Find the correct combination of A, B, C and D inputs which can cause the LED to glow. [Figure: A feeds a NOR… JEE Main 22nd Jan 1st Shift 2026
• The correct truth table for the given input data of the following logic gate is [Figure: A and B feed an AND… JEE Main 22nd Jan 2nd Shift 2026
• For the given logic gate circuit, which of the following is the correct truth table? [Figure: n and m feed an… JEE Main 23rd Jan 2nd Shift 2026
• Identify the correct truth table of the given logic circuit. [Figure: A feeds an AND gate with both inputs ti… JEE Main 24th Jan 2nd Shift 2026
• Two p-n junction diodes D₁ and D₂ are connected as shown in figure. A and B are input signals and C is the ou… JEE Main 28th Jan 2nd Shift 2026
• In the digital circuit shown in the figure, for the given inputs the P and Q values are [Figure: both inputs… JEE Main 2nd April 2nd Shift 2025
• Choose the correct logic circuit for the given truth table having inputs A and B. Truth table (A, B, Y): 0 0… JEE Main 3rd April 1st Shift 2025
• The truth table corresponding to the circuit given below is [Figure: A and B feed an OR gate; the OR output a… JEE Main 3rd April 2nd Shift 2025
• The Boolean expression Y=ABC+AC can be realised with which of the following gate configurations. A. One 3-inp… JEE Main 4th April 1st Shift 2025
• Consider the following logic circuit. The output is Y=0 when [Figure: A and B feed an AND gate. B and A (from… JEE Main 7th April 2nd Shift 2025
• The output of the circuit is low (zero) for: (A) X=0,Y=0 (B) X=0,Y=1 (C) X=1,Y=0 (D) X=1,Y=1. Choose the corr… JEE Main 24th Jan 2nd Shift 2025
• Which of the following circuits has the same output as that of the given circuit? [Figure: A and B drive two… JEE Main 28th Jan 1st Shift 2025
• For the circuit shown above, equivalent gate is [Figure: A and B feed a NAND gate and also a NOR gate; the tw… JEE Main 29th Jan 1st Shift 2025
• The truth table for the circuit given below is [Figure: upper AND gate with inputs A and B; lower AND gate wi… JEE Main 29th Jan 2nd Shift 2025
• Identify the logic gate given in the circuit. [Figure: A and B each pass through a NOT gate; the two outputs… JEE Main 4th April 2nd Shift 2024
• Following gates section is connected in a complete suitable circuit. For which of the following combination,… JEE Main 5th April 1st Shift 2024
• The output (Y) of logic circuit given below is 0 only when [Figure: A and B feed an OR gate; B and a constant… JEE Main 5th April 2nd Shift 2024
• The correct truth table for the following logic circuit is [Figure: A passes through a NOT gate into an OR ga… JEE Main 6th April 1st Shift 2024
• The output Y of following circuit for given input is [Figure: an OR gate with inputs A and B; an AND gate wit… JEE Main 8th April 1st Shift 2024
• In the truth table of the above circuit the value of X and Y are [Figure: an AND gate with inputs A and B, an… JEE Main 9th April 2nd Shift 2024
• The truth table of the given circuit diagram is [Figure: upper AND gate with inputs A and B; lower AND gate w… JEE Main 27th Jan 2nd Shift 2024
• The truth table for this given circuit is [Figure: upper AND gate with inputs A and B; lower AND gate with in… JEE Main 29th Jan 2nd Shift 2024
• Identify the logic operation performed by the given circuit. [Figure: A and B each pass through a NOT gate in… JEE Main 31st Jan 1st Shift 2024 (also JEE Main 9th April 2nd Shift 2019)
• The output of the given circuit diagram is [Figure: an upper OR gate with inputs A and B; a lower OR gate wit… JEE Main 31st Jan 2nd Shift 2024
• Name the logic gate equivalent to the diagram attached [Figure: a +5 V supply feeds the top wire of a rectang… JEE Main 6th April 1st Shift 2023
• For the logic circuit shown, the output waveform at Y is [Figure: A is 0 from 0 to 2 and 1 from 2 to 4. B is… JEE Main 8th April 1st Shift 2023
• The logic performed by the circuit shown in figure is equivalent to [Figure: a and b each go into a NOR gate… JEE Main 11th April 1st Shift 2023
• The logic operations performed by the given digital circuit is equivalent to [Figure: A and B feed an OR gate… JEE Main 11th April 2nd Shift 2023
• The output from a NAND gate having inputs A and B given below will be [Figure: time is split into seven inter… JEE Main 13th April 2nd Shift 2023
• The logic gate equivalent to the given circuit diagram is [Figure: a +5 V supply feeds a top wire. On the lef… JEE Main 24th Jan 2nd Shift 2023
• The output waveform of the given logical circuit for the following inputs A and B as shown below, is [Figure:… JEE Main 30th Jan 1st Shift 2023
• The output Y for the inputs A and B of circuit is given by [Figure: four NAND gates. A and B feed NAND 1. NAN… JEE Main 30th Jan 2nd Shift 2023
• In the circuit, the logical value of A=1 or B=1 when potential at A or B is 5 V and the logical value of A=0… JEE Main 30th Jan 2nd Shift 2023
• A logic gate circuit has two inputs A and B and output Y. The voltage waveforms of A, B and Y are shown below… JEE Main 27th July 1st Shift 2022
• Identify the logic operation performed by the given circuit [Figure: A and B each go into a NOR gate with tie… JEE Main 25th June 2nd Shift 2022
• Identify the correct logic gate for the following output (Y) of two inputs A and B. [Figure: seven equal inte… JEE Main 27th June 1st Shift 2022
• In the following circuit, the correct relation between output (Y) and inputs A and B will be [Figure: inputs… JEE Main 28th June 1st Shift 2022
• Identify the logic operation carried out by the given circuit. [Figure: A and B each go into a NAND gate with… JEE Main 26th Aug 1st Shift 2021
• Four NOR gates are connected as shown in figure. The truth table for the given figure is [Figure: A and B fee… JEE Main 26th Aug 2nd Shift 2021
• In the following logic circuit the sequence of inputs A, B are (0,0), (0,1), (1,0) and (1,1). The output Y fo… JEE Main 31st Aug 1st Shift 2021
• If V_A and V_B are the input voltages (either 5 V or 0 V) and V₀ is the output voltage then the two gates rep… JEE Main 31st Aug 2nd Shift 2021
• Identify the logic operation carried out. [Figure: A and B each go into a NAND gate with tied inputs; the out… JEE Main 25th July 1st Shift 2021
• Find the truth table for the function Y of A and B represented in the following figure. [Figure: A and B feed… JEE Main 27th July 2nd Shift 2021
• The following logic gate is equivalent to [Figure: A and B each go into a NAND gate with tied inputs; the out… JEE Main 16th March 2nd Shift 2021
• The output of the given combination gates represents [Figure: A and B each go into a NOR gate with tied input… JEE Main 17th March 1st Shift 2021
• Which one of the following will be the output of the given circuit? [Figure: A and B feed an AND gate followe… JEE Main 17th March 2nd Shift 2021
• The logic circuit shown above is equivalent to [Figure: A and B (B through a NOT gate) feed an OR gate, follo… JEE Main 24th Feb 2nd Shift 2021
• The truth table for the following logic circuit is [Figure: upper AND gate with inputs A and B; lower AND gat… JEE Main 25th Feb 2nd Shift 2021
• Draw the output signal Y in the given combination of gates. [Figure: A is 1 from 0 to 2 s, 0 from 2 to 3 s, 1… JEE Main 26th Feb 2nd Shift 2021
• In the following digital circuit, what will be the output at Z, when the input (A,B) are (1,0), (0,0), (1,1),… JEE Main 2nd Sept 2nd Shift 2020
• Identify the operation performed by the circuit given below [Figure: A, B and C each go into a NOR gate with… JEE Main 4th Sept 2nd Shift 2020
• Which of the following gives a reversible operation? [Figure: (a) a two-input NOR gate; (b) a NOR gate with b… JEE Main 7th Jan 1st Shift 2020
• Boolean relation at the output stage-Y for the following circuit is [Figure: a 5 V source connects through sw… JEE Main 8th Jan 1st Shift 2020
• In the given circuit, value of Y is [Figure: input 1 passes through a NOT gate; its output feeds both inputs… JEE Main 8th Jan 2nd Shift 2020
• The truth table for the circuit given in the figure is [Figure: A and B feed an OR gate; the OR output and A… JEE Main 12th April 1st Shift 2019
• The output of the given logic circuit is [Figure: A and B feed NAND 1. NAND 2 takes A and the NAND 1 output.… JEE Main 12th Jan 1st Shift 2019
• Truth table for the following digital circuit will be [Figure: an AND gate with inputs x and y, and a second… JEE Main Online 2018
• If a, b, c, d are inputs to a gate and x is its output, then, as per the following time graph, the gate is [F… JEE Main 2016
• The truth table given in figure represents: A, B, Y: 0 0 0; 0 1 1; 1 0 1; 1 1 1. JEE Main Online 2016
• To get an output of 1 from the circuit shown in figure the input must be [Figure: a and b feed an OR gate; it… JEE Main Online 2016
• Given: A and B are input terminals. Logic 1 = >5 V, Logic 0 = <1 V. Which logic gate operation the following… JEE Main Online 2014
• Which logic gate with inputs A and B performs the same operation as that performed by the following circuit?… JEE Main Online 2012
• The output of an OR gate is connected to both the inputs of a NAND gate. The combination will serve as a JEE Main 2011
• The combination of gates shown below yields [Figure: A and B each go into a NAND gate with tied inputs; the o… JEE Main 2010
• The logic circuit shown below has the input waveforms A and B as shown. Pick out the correct output waveform.… JEE Main 2009
• In the circuit below, A and B represent two inputs and C represents the output. The circuit represents [Figur… JEE Main 2008
• In the logic circuit shown in the figure, if input A and B are 0 to 1 respectively, the output at Y would be… JEE Main 16th March 1st Shift 2021