0
What else can I help you with?
Why diode logic gate is not suitable for cascading operation?
the pullup or pull down resistance in the diode logic gate makes it a high output resistance device.If u try to drive another diode logic gate with it the output voltage of the first gate will be affected by the resistance in the second gate.A diode logic gate should always drive a high input resistance input.
How NAND gate works?
A: NAND implies not and to be true both input must be hi or true <> There are two flavors of NAND gate. The positive input/negative output NAND will have a low output if and only if both inputs are high. The negative input/positive output NAND will have a high output if and only if both inputs are low.
The value of r when a transistor is biased to cut off is -?
Collector-to-Emitter resistance is high when the transistor is biased off.
What is the function of the IC 7404?
It will give high output when the given input is low and also give LOW output when the given input is high (Vice versa).
Working process of 555 timer?
Comparator 1 has a threshold input (pin 6) and a control input (pin 5). In most applications, the control input is not used, so that the control voltage equals +2/3 VCC. Output of this comparator is applied to set (S) input of the flip-flop. Whenever the threshold voltage exceeds the control voltage, comparator 1 will set the flip-flop and its output is high. Ahigh output from the flip-flop saturates the discharge transistor and discharge the capacitor connected externally to pin 7. The complementary signal out of the flip-flop goes to pin 3, the output. The output available at pin 3 is low. These conditions will prevail until comparator 2 triggers the flip-flop. Even if the voltage at the threshold input falls below 2/3 VCC,that is comparator 1 cannot cause the flip-flop to change again. It means that the comparator 1 can only force the flip-flop's output high.To change the output of flip-flop to low, the voltage at the trigger input must fall below + 1/3 Vcc. When this occurs, comparator 2 triggers the flip-flop, forcing its output low. The low output from the flip-flop turns the discharge transistor off and forces the power amplifier to output a high. These conditions will continue independent of the voltage on the trigger input. Comparator 2 can only cause the flip-flop to output low.From the above discussion it is concluded that for the having low output from the timer 555, the voltage on the threshold input must exceed the control voltage or + 2/3 VCC. They also turn the discharge transistor on. To force the output from the timer high, the voltage on the trigger input must drop below +1/3 VCC. This also turns the discharge transistor off.A voltage may be applied to the control input to change the levels at which the switching occurs. When not in use, a 0.01 nano Farad capacitor should be connected between pin 5 and ground to prevent noise coupled onto this pin from causing false triggering.Connecting the reset (pin 4) to a logic low will place a high on the output of flip-flop. The discharge transistor will go on and the power amplifier will output a low. This condition will continue until reset is taken high. This allows synchronization or resetting of the circuit's operation. When not in use, reset should be tied to +VCC.
Why transistor is called transfer of resistor?
Transistor=Transfer+Resistor. When Transistor operates in active region its input resistance is high and output resistance is low. So,We can consider transistor as a device which transfers its resistance from high to low. And by this property transistor amplifies input signal.
What is the work of transistor?
The work of a transistor is to amplify the input signal to get high output value.
Why is a Junction transistor so named?
In a transistor a current from low resistance input circuit is transferred to a high resistance output circuit with almost unchanged magnitude. This results in a power gain. Infact the name 'transistor' is coined from 'transfer resistor'
What happens when high input signal is given to pnp transistor?
A high signal input to a transistor amplifier gives a high signal output provided it stays linear.
How many possible states does a transistor have?
The transistor is a semi conductor. The materials in which it is constructed has three terminals and which to connect to external input. The connection in addition has another terminal which changes current. Therefore the output is high input is lower.
Why the voltage gain of an FET amplifier is generally less than that obtained using BJT amplifier?
A FET (Field Effect Transistor) is mainly used when the input signal needs to be isolated from the output. A FET has a very high input resistance, so very little current is required from the input. Voltage gain is not the main objective when using a FET.
What gate the output will be low for any case when one or more input are zero?
An inverter has a high output when the input is low, and a low output when the input is high.
How do design a high voltage voltmeter?
Use a voltage divider and an standard high input impedance voltmeter connected to the low voltage output tap of the divider. Just check that: a) the voltage divider has enough resistance to minimize loading of the voltage source (The voltage divider resistance should be as high as possible). b) the voltmeter's input impedance is at least 10-20 times larger than the output resistance (impedance) of the divider. If necessary add a high-input impedance amplifier or a transducer between the divider output and the voltmeter. What is high voltage for you?
Why diode logic gate is not suitable for cascading operation?
the pullup or pull down resistance in the diode logic gate makes it a high output resistance device.If u try to drive another diode logic gate with it the output voltage of the first gate will be affected by the resistance in the second gate.A diode logic gate should always drive a high input resistance input.
Is the input resitance of an ideal ammeter is low and the output resistance is high?
An ammeter does not have an 'output resistance'. It's important that its resistance is low so as not to add additional resistance into the circuit to which it is connected, otherwise the 'measured current' would be lower than the actual current.
Why the input impedence of op-Amp is very high?
An ideal amplifier will have a very high input resistance, and low output resistance. This is so it doesn't "load" the input circuitry, and can drive output circuitry. Say you hooked an op amp up to a microphone that kicked out 100mV unloaded. If you shorted out the microphone, the output would approach 0mV (very low resistance load). If you connected a very high resistance load instead, the output would remain close to 100mV. As the load becomes a smaller resistance/bigger load, the output voltage will decrease until it is no longer useful. This is because the microphone has an internal resistance that remains constant while you're varying the attached load. The voltage drop across the internal resistance will increase as current output increases, causing less of a signal to be delivered to the amplifier.
How do you make an eight input AND gate out of transistors?
One way to make an eight input AND gate out of transistors... Start with one transistor, NPN. Ground the emitter. Connect the collector to Vcc with a resistor. Connect the base to Vcc through two resistors, picked to drive the transistor into saturation. The input of that stage is the junction of the two resistors. If you ground that input, the transistor cuts off, and the collector goes high. Unground the input, and the collector goes low. OK. Now you have an inverter. Build eight of them, but only use one collector resistor, and tie all of the collectors together. If any one input is high, the output is low. If all inputs are low, the output is high. OK. Now you have an 8 input negative logic NAND gate. Follow it up with another inverter stage, reversing the output. OK. Now you still have an 8 input NAND gate, with the output high true. If you want the inputs to be high true also, connect each one to an inverter. This will use 17 transistors, and you will have an 8 input positive logic AND gate.
