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What is the maximum resistance you want to see across a switch?
The maximum resistance across a switch should be infinite.
What voltage would you expect to measure across closed switch?
Original Correct Answer:The voltage across an open switch should equal the supply voltage.More Detailed Answer:The above answer is basically correct. However, it may not be EXACTLY the supply voltage.This is counter-intuitive at first glance and confuses a lot of people, including electrical engineers. The reason is this. Voltage, Current and Resistance are all interrelated by Ohms Law. Voltage equals Current multiplied by Resistance.It is easy to think that since a switch is open, then you do not have current flow through the circuit. Thus, current times any Resistance is equal to zero volts because the current is equal to zero. Thus, by this logic, you would expect to find zero volts across the switch. In actuality this is true.But, when you insert you meter, you change the conditions of the circuit, and the following is the result.Let's say that you have a circuit with a resistance load like a heater, and a inductive load like a motor. The switch that powers these devices is open, thus their is no current flowing through the resistance or inductive loads.Now you put the meter across the open switch. When you do, you insert a very large resistance in parallel to the open switch. Why? Because to get volts, the meter measures current flow through a known resistance, and then calculates voltage. To keep the resistance from impacting the circuit performance, the resistance is very large. Therefore, when you insert the meter, you will get a flow of current through the meter.Because of this large resistance, the current trough the resistance load, inductive load, and wires is very small. Thus, the voltage drop across the loads and wiring is very small. Therefore, it appears that the entire voltage in the circuit is across the huge resistance in the meter. The result is a voltage reading that is very near the source voltage.Let's do the math. Let's assume you have 120 volts. You also have a resistance of 500 ohms, and a motor winding that has 0 ohms resistance when DC is applied (This is true for motors). The meter has a 10 million ohm resistance.If these loads are in series, the total resistance is 10Million 500 ohms. The 11.9 microamps. By multiplying the current flow to each resistance, you get 6 millivolts across the resistance, no voltage across the motor winding, and 119.994 across the open switch or meter. Since a meter rounds it reading, you would get 120.If the loads are in parellel, you would get the same thing, becuase the switch is in series with both loads. In this example, the motor winding would have all the current flow through it since it is zero ohms, and the parallel resitance load is 500 ohms. Thus, the total resistance is the 10 million of the meter, and this resistance drive the current, and thus the largest voltage drop is at the swtich/meter. You could decide to remove the motor from this parellel circuit. If you did then the then the result is the series circuit above.
What would happen to circuit if there was no resistance?
a circuit with no resistance or zero resistance can be considered as open circuit in which the current is zero. without resistance the circuit just becomes open ()
Is 160 ohms reading on a switch bad?
For a switch the reading should be in the zero ohm range. Corrosion or pitted contacts will start to raise the resistance rating on a switch. This size of rating on the switch will start to raise the temperature of the switch because the switch starts to act like a load in the circuit.
Is the pressure switch high Normally open or normally close?
A pressure switch can be normally open or normally closed. It depends on how it was made. The NO/NC should be marked somewhere on the switch. A pressure switch can be normally open or normally closed. It depends on how it was made. The NO/NC should be marked somewhere on the switch.
Will an open switch record a resistance of zero ohms?
no...... ideal open switch should have a resistance of infinity... the question should be a closed switch http://wiki.answers.com/Q/Will_an_open_switch_record_a_resistance_of_zero_ohms" but this is also false because any good conductor will have a small resistance the connecting wire resistance is exhibitted across the terminals of the switch
Is a switch and example of a resistor?
No it is not. A resistor has a known resistance that is less than infinity. A switch has a resistance of either infinity when it is open or low when it is closed
What is the difference between open and close switch?
In an open circuit no cuttent can flow so the switch would have to be in the off position- the switch is open and not completing the circuit. A closed circuit is one where current can flow all the way through, the switch would have to on and therefore closed.
How can you do the polarity test of a switch?
A 'polarity test', as it applies to a switch, is performed to confirm that the switch is located in the line conductor and not in the neutral conductor.
What is the maximum resistance you want to see across a switch?
The maximum resistance across a switch should be infinite.
A battery has emf of 6 v and an internal resistance of 4 ohm it is connected to a 2.6 ohm resistor a switch when switch is open the potential difference between the terminals of a battery is?
6 volts
What is the continuity reading on a pressure switch in a power vent water heater marked normally open and -1.07PF when the blower is off?
If the pressure switch is marked as normally open, there should be continuity (zero resistance) through the switch when the blower is off. The reading of -1.07PF signifies the pressure setting at which the switch should close to allow the blower to turn on.
Is a switch a resistor?
It could act as one when the circuit is closed, but when the circuit is open, I believe you would define the air as the thing resisting current. In basic circuit problems the switch usually doesn't have any resistance of its own (ie as negligible as the resistance in a wire, so it is ignored).
How does a switch control an electric device?
A switch basically represents a gap in the electric circuit. Electric current can pass through a circuit only if it is complete. An incomplete circuit can never pass a current through it. When the switch is in the 'off' position, the circuit has a break (gap) in it. When you put the switch in 'on' position, the circuit wire join and the circuit gets completed.
What happens if the switch is open?
If the switch is open, current does not flow.
What voltage would you expect to measure across closed switch?
Original Correct Answer:The voltage across an open switch should equal the supply voltage.More Detailed Answer:The above answer is basically correct. However, it may not be EXACTLY the supply voltage.This is counter-intuitive at first glance and confuses a lot of people, including electrical engineers. The reason is this. Voltage, Current and Resistance are all interrelated by Ohms Law. Voltage equals Current multiplied by Resistance.It is easy to think that since a switch is open, then you do not have current flow through the circuit. Thus, current times any Resistance is equal to zero volts because the current is equal to zero. Thus, by this logic, you would expect to find zero volts across the switch. In actuality this is true.But, when you insert you meter, you change the conditions of the circuit, and the following is the result.Let's say that you have a circuit with a resistance load like a heater, and a inductive load like a motor. The switch that powers these devices is open, thus their is no current flowing through the resistance or inductive loads.Now you put the meter across the open switch. When you do, you insert a very large resistance in parallel to the open switch. Why? Because to get volts, the meter measures current flow through a known resistance, and then calculates voltage. To keep the resistance from impacting the circuit performance, the resistance is very large. Therefore, when you insert the meter, you will get a flow of current through the meter.Because of this large resistance, the current trough the resistance load, inductive load, and wires is very small. Thus, the voltage drop across the loads and wiring is very small. Therefore, it appears that the entire voltage in the circuit is across the huge resistance in the meter. The result is a voltage reading that is very near the source voltage.Let's do the math. Let's assume you have 120 volts. You also have a resistance of 500 ohms, and a motor winding that has 0 ohms resistance when DC is applied (This is true for motors). The meter has a 10 million ohm resistance.If these loads are in series, the total resistance is 10Million 500 ohms. The 11.9 microamps. By multiplying the current flow to each resistance, you get 6 millivolts across the resistance, no voltage across the motor winding, and 119.994 across the open switch or meter. Since a meter rounds it reading, you would get 120.If the loads are in parellel, you would get the same thing, becuase the switch is in series with both loads. In this example, the motor winding would have all the current flow through it since it is zero ohms, and the parallel resitance load is 500 ohms. Thus, the total resistance is the 10 million of the meter, and this resistance drive the current, and thus the largest voltage drop is at the swtich/meter. You could decide to remove the motor from this parellel circuit. If you did then the then the result is the series circuit above.
What would happen to circuit if there was no resistance?
a circuit with no resistance or zero resistance can be considered as open circuit in which the current is zero. without resistance the circuit just becomes open ()
