Advertisements
Advertisements
प्रश्न
Write the truth table for circuit given in figure below consisting of NOR gates and identify the logic operation (OR, AND, NOT) which this circuit is performing.
(Hint: A = 0, B = 1 then A and B inputs of second NOR gate will be 0 and hence Y=1. Similarly work out the values of Y for other combinations of A and B. Compare with the truth table of OR, AND, NOT gates and find the correct one.)
उत्तर
A and B are the inputs of the given circuit. The output of the first NOR gate is `bar(A +B)`. It can be observed from the following figure that the inputs of the second NOR gate become the out put of the first one.
Hence, the output of the combination is given as:
`Y = bar(bar("A+B") + bar("A+B")) = bar(bar("A").bar("B")) + bar(bar"A".bar"B")`
`= bar(bar"A".bar"B") = bar(bar"A") + bar(bar"B") = "A + B"`
The truth table for this operation is given as:
| A | B | Y (=A + B) |
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
This is the truth table of an OR gate. Hence, this circuit functions as an OR gate.
APPEARS IN
संबंधित प्रश्न
The output of NOR gate is high, when _______.
The following figure shows the input waveforms (A, B) and the output waveform (Y) of a gate. Identify the gate, write its truth table and draw its logic symbol.
The logic gate which produces LOW output when one of the input is HIGH and produces
HIGH output only when all of its inputs are LOW is called _______.
(A) AND gate
(B) OR gate
(C) NOR gate
(D) NAND gate
You are given two circuits as shown in following figure, which consist of NAND gates. Identify the logic operation carried out by the two circuits.
(a)
(b)
Give the truth table and circuit symbol for NAND gate
The arrangement given below represents a logic gate :
Copy the following truth table in your answer booklet and complete it showing outputs at C
and D.
| A | B | C | D |
| 0 | 0 | ||
| 1 | 0 | ||
| 0 | 1 | ||
| 1 | 0 |
Draw logic symbol of an OR gate and write its truth table.
What will be the values of input A and B for the Boolean expression `overline ((A +B) .(A*B)) =1?`
The output of an OR gate is connected to both the inputs of a NAND gate Draw the logic circuit of this combinaion of getes and write its truth table.
Let \[X = A \overline{ BC} + B\overline{ CA} + C\overline{AB } .\] Evaluate X for A = B = C = 1.
Let \[X = A \overline{ BC} + B\overline{ CA} + C\overline{AB } .\] Evaluate X for A = B = C = 0.
(i) Write the truth tables of the logic gates marked P and Q in the given circuit.
(ii) Write the truth table for the circuit.
Why are NOR gates considered as universal gates?
Draw a diagram to show how NAND gates can be combined to obtain an OR gate. (Truth table is not, required)
Useful Constants and Relations:
| 1. | Charge of a proton | (e) | =1.6 × 10-19C |
| 2. | Planck's constant | (h) | = 6·6 × 10-34 Js |
| 3. | Mass of an electron | (m) | = 9·1× 10-31 kg |
| 4. | Permittivity of vacuum | (∈0) | =8 · 85 × 10-12 Fm-1 |
| 5. | `(1/(4pi∈_0))` | =9 ×109 mF-1 | |
| 6. | Permeability of vacuum | (μ0) | = 4π × 10-7 Hm-1 |
| 7. | `((mu_0)/(4pi))` | =1 × 10-7 Hm-1 | |
| 8. | Speed of light in vacuum | (c) | = 3× 108 ms-1 |
| 9. | Unified atomic mass unit | (u) |
= 931 MeV |
| 10. | Electron volt | (leV) | = 1.6 × 10-19 J |
In potential barrier development in a junction diode opposes
Two car garages have a common gate which needs to open automatically when a car enters either of the garages or cars enter both. Devise a circuit that resembles this situation using diodes for this situation.
How would you set up a circuit to obtain NOT gate using a transistor?
Draw the output signals C1 and C2 in the given combination of gates (Figure).
Which one of the following is the Boolean expression for NOR gate?
