Logic Gates

Q. The correct Boolean operation represented by the circuit diagram drawn is

1. AND
2. OR
3. NAND
4. NOR

Q. Find the current through the middle branch of the unbalanced Wheatstone's bridge circuit, as shown in figure.

1. $0.460\text{A}$
2. $0.023\text{A}$
3. $0.1\text{A}$
4. $0.046\text{A}$

Q. When a diode is forward biased, it has a voltage drop of $0.5\text{V}.$ The safe limit of current through the diode is $10\text{mA}$. If a battery of emf $1.5\text{V}$ is used in a circuit. The value of minimum resistance to be connected in series with the diode so that the current does not exceed the safe limit is-

1. $300\Omega$
2. $50\Omega$
3. $100\Omega$
4. $200\Omega$

Q.

Which of the following is the universal gate?

1. OR

2. NOT

3. AND

4. NAND

Q. If power dissipated in the $9\Omega$ resistor in the circuit shown in $36\text{W}$, the potential difference across the $2\Omega$ resistor is

1. $8\text{Volt}$
2. $4\text{Volt}$
3. $2\text{Volt}$
4. $10\text{Volt}$

Q.

Which of the following is not a network topology

1. bus

2. ring

3. star

4. connect

Q.

The following logic gate is equivalent to:

1. NOR Gate

2. AND Gate

3. OR Gate

4. NAND Gate

Q. The combination of the gate shown below produces

1. $AND$ gate
2. $NAND$ gate
3. $NOR$ gate
4. $OR$ gate

Q. In the combination of the following gates, the output Y can be written in terms of inputs A and B as

1. $\overline{A.B}$
2. $A\overline{.B}+\overline{A}.B$
3. $\overline{A.B}+A.B$
4. $\overline{A+B}$

Q.

Which of the following is the universal gate?

1. OR gate

2. AND gate

3. NAND gate

4. NOT gate

Q. How many NAND gates are used in an OR gate?

1. Four
2. Two
3. Three
4. Five

Q. For the forward biased diode characteristics shown in the figure, the dynamic resistance at $I_D=3mA$ will be ____ $\Omega$.

Q. Which of the following is not equal to $1$ in boolean algebra?

1. $A+1$
2. $A.\overline{A}$
3. $A+\overline{A}$
4. $\overline{A.A}$

Q. A closely wound solenoid of $2000$ turns and area of cross-section $1.5\times {10}^{–4}{\text{m}}^2$ carries a current of $2.0\text{A}$. It is suspended through its centre and perpendicular to its length, allowing it to turn in a horizontal plane in a uniform magnetic field $5\times {10}^{–2}\text{tesla}$ making an angle of ${30}^{\circ }$ with the axis of the solenoid. The torque on the solenoid will be

1. $1.5\times {10}^{-3}\text{Nm}$
2. $3\times {10}^{-2}\text{Nm}$
3. $3\times {10}^{-3}\text{Nm}$
4. $1.5\times {10}^{-2}\text{Nm}$

Q.

The NOR gate is OR gate followed by

1. AND gate

2. OR gate

3. NOT gate

4. None of the above

Q. For the given combination of gates, if the logic states of inputs A, B, C are as follows A = B = C = 0 and A = B = 1, C = 0 then the logic states of output D are

1. 0, 0
2. 0, 1
3. 1, 0
4. 1, 1

Q. Which of the following gates will have an output of 1?

1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (d) and (a)

Q. The combination of ‘NAND’ gates shown here under (figure) are equivalent to –

1. An OR gate and an AND gate respectively
2. An AND gate and a NOT gate respectively
3. An AND gate and an OR gate respectively
4. An OR gate and a NOT gate respectively

Q. In the circuit as shown in the figure, the heat produced by $6\Omega$ resistance due to current flowing in it is $60$ calorie per second. The heat generated across $3\Omega$ resistance per second will be

1. $60cal/s$
2. $30cal/s$
3. $120cal/s$
4. $100cal/s$

Q.

Can A Diode Act As A Switch

Q.

The logic circuit shown below is equivalent to :

1. 

2. 

3. 

4. 

Q. A logic gate circuit has two inputs $A$ and $B$ and output $Y$. The voltage waveforms of $A,B$ and $Y$ are shown below.


The logic gate circuit is :

Q. The truth table for the circuit given in the figure is :

1. $\left[\begin{array}{ccc}A& B& Y\\ 0& 0& 1\\ 0& 1& 1\\ 1& 0& 0\\ 1& 1& 0\end{array}\right]$
2. $\left[\begin{array}{ccc}A& B& Y\\ 0& 0& 1\\ 0& 1& 0\\ 1& 0& 0\\ 1& 1& 0\end{array}\right]$
3. $\left[\begin{array}{ccc}A& B& Y\\ 0& 0& 1\\ 0& 1& 1\\ 1& 0& 1\\ 1& 1& 1\end{array}\right]$
4. $\left[\begin{array}{ccc}A& B& Y\\ 0& 0& 0\\ 0& 1& 0\\ 1& 0& 1\\ 1& 1& 1\end{array}\right]$

Q. Two headlights on a car are wired in_______

1. Series
2. Parallel
3. Series or parallel, we cannot say
4. parallel in some car & in series in other car

Q. The output $Y$ of the gate shown in the figure will be represented by :

1. $Y=A\cdot B$
2. $Y=A+B$
3. $Y=\overline{A+B}$
4. $Y=A\overline{B}+B\overline{A}$

Q.

How many transistors are in $A3NAND$ gate?

Q.

The Boolean equation for the circuit given in the figure:

1. $Y=\overline{A}.B+C$

2. $Y=\overline{A}.(\overline{B}+\overline{C})$

3. $Y=\overline{A}(B+C)$

4. $Y=\overline{A}.(B+\overline{C})$

Q.

The truth table for system of four NAND gates as shown in the figure is

1. $\begin{array}{ccc}A& B& Y\\ 0& 0& 0\\ 0& 1& 0\\ 1& 0& 1\\ 1& 1& 1\end{array}$

2. $\begin{array}{ccc}A& B& Y\\ 0& 0& 1\\ 0& 1& 1\\ 1& 0& 0\\ 1& 1& 0\end{array}$

3. $\begin{array}{ccc}A& B& Y\\ 0& 0& 1\\ 0& 1& 0\\ 1& 0& 0\\ 1& 1& 1\end{array}$

4. $\begin{array}{ccc}A& B& Y\\ 0& 0& 0\\ 0& 1& 1\\ 1& 0& 1\\ 1& 1& 0\end{array}$

Q. The logic circuit shown below has the input waveforms $\text{A}$ and $\text{B}$ as shown in the figure. Pick the correct output waveform

1. 
2. 
3. 
4. 

Q.

A logic gate is an electronic circuit which

1. Makes logic decisions

2. Works binary algebra

3. Allows electrons flow only in one direction

4. Alternates between 0 and 1 values