The binary number is equivalent to the decimal number
1
19
2
31
3
23
4
22
Official Solution
Correct Option: (3)
Hence,
02
PYQ 2010
medium
physicsID: wbjee-20
The decimal equivalent of the binary number is
1
9.625
2
25.265
3
26.625
4
26.265
Official Solution
Correct Option: (3)
The decimal equivalent can be found as follows,
03
PYQ 2018
medium
physicsID: wbjee-20
In the circuit shown, inputs and are in states ? ? and ? ? respectively. What is the possible stable state of the outputs ? ? and ? ? ?
1
X = 1, Y = 1
2
X = 1, Y = 0
3
X = 0,Y = 1
4
X = 0, Y =0
Official Solution
Correct Option: (3)
04
PYQ 2022
medium
physicsID: wbjee-20
The expression simplifies to
1
A+B
2
AB
3
4
Official Solution
Correct Option: (1)
The given expression is .
Step 1: Simplify First, expand :
Step 2: Simplify Next, observe that , so we can rewrite the second part: Now expand:
Step 3: Combine both parts Now, combine the two parts of the expression: Simplifying this:
Step 4: Factor the expression The final simplified expression is: Thus, the answer is .
05
PYQ 2023
hard
physicsID: wbjee-20
Consider the logic circuit with inputs A,B,C, and output Y. How many combinations of A, B and C give the output Y=0?
1
8
2
5
3
7
4
1
Official Solution
Correct Option: (3)
In a logic circuit with inputs A, B, and C, each input can take values 0 or 1. Since there are three binary inputs, the total number of input combinations is:
We are interested in the number of combinations that result in output .
From the logic of the circuit, the combinations that result in are:
, ,
, ,
, ,
, ,
, ,
, ,
, ,
So, the number of combinations giving output is 7.
Correct option: (C): 7
06
PYQ 2025
hard
physicsID: wbjee-20
Which logic gate is represented by the following combination of logic gates?
1
NAND
2
AND
3
NOR
4
OR
Official Solution
Correct Option: (1)
Step 1: Understanding the Circuit - The circuit consists of two NOT gates and an AND gate.
- Input passes through a NOT gate to become .
- Input also passes through a NOT gate to become .
- The outputs of these NOT gates, and , are then fed into an AND gate.
- The AND gate will output . Step 2: Recognizing the Gate Type The circuit represents a NAND gate because the output is the negation of the AND operation. This is equivalent to , which is the definition of a NAND gate. Step 3: Conclusion The correct answer is:
07
PYQ 2026
medium
physicsID: wbjee-20
Which logic gate is represented by the following combinations of logic gates?
1
NAND
2
AND
3
NOR
4
OR
Official Solution
Correct Option: (1)
Concept: Use De Morgan's laws. Step 1: {\color{red}Identify components.} - Inputs A and B first pass through NOT gates ⇒ . - These go into OR gate with inversion at output ⇒ NOR of inverted inputs. Step 2: {\color{red}Expression.} Step 3: {\color{red}Apply De Morgan.} But inversion at output gives complement: Step 4: {\color{red}Conclusion.} This is NAND gate.
