VOM Reading
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1. At which end of the ohmmeter scale is the resistance reading more reliable,the crowded or the uncrowded end? Generally an ohmmeter will be more accurate near the middle to upper range or the selected range - this is because it will be rated at an error of a certain ohm + / - a certain percentage. As you increase, the base ohms stays the same, but becomes a smaller percentage. 2. What is meant by an open circuit? Short circuit? Open- an incomplete electrical circuit in which no current flows. An electric circuit in which the normal path of current has been interrupted, either by the disconnection of one part of its conducting pathway from another, or by the intervention of an electric component, such as a transistor. Short- a faulty or accidental connection between two points of different potential in an electric circuit, bypassing the load and establishing a path of low resistance through which an excessive current can flow. It can cause damage to the components if the circuit is not protected by a fuse 3. What is the ohmmeter reading for an open circuit? Short circuit? The highest value or 'infinity' for o.c. and the lowest value or 'zero' for s.c. on the Ohmmeter dial. 4. Describe briefly how would you check a 50 Mega ohm resistor to see if it is open. State two precautions to make sure the check is not misleading. 5. How can a potentiometer be a rheostat? A rheostat and a potentiometer are two different applications for the same device, a variable resistor. These devices have three terminals. Two terminals are connected across the complete resistor, while the third terminal is connected to a controllable wiper. The variable resistance is provided between the wiper terminal and either one of the other two terminals. When used to control current, it is called a rheostat. When used to control voltage, it is called a potentiometer.
Transcript of VOM Reading
1. At which end of the ohmmeter scale is the resistance reading more reliable,the crowded or the uncrowded end?Generally an ohmmeter will be more accurate near the middle to upper range or the selected range - this is because it will be rated at an error of a certain ohm + / - a certain percentage. As you increase, the base ohms stays the same, but becomes a smaller percentage.
2. What is meant by an open circuit? Short circuit?Open- an incomplete electrical circuit in which no current flows. An electric circuit in which the normal path of current has been interrupted, either by the disconnection of one part of its conducting pathway from another, or by the intervention of an electric component, such as a transistor.
Short- a faulty or accidental connection between two points of different potential in an electric circuit, bypassing the load and establishing a path of low resistance through which an excessive current can flow. It can cause damage to the components if the circuit is not protected by a fuse
3. What is the ohmmeter reading for an open circuit? Short circuit?
The highest value or 'infinity' for o.c. and the lowest value or 'zero' for s.c. on the Ohmmeter dial.
4. Describe briefly how would you check a 50 Mega ohm resistor to see if it is open. State two precautions to make sure the check is not misleading.
5. How can a potentiometer be a rheostat?A rheostat and a potentiometer are two different applications for the same device, a variable resistor. These devices have three terminals. Two terminals are connected across the complete resistor, while the third terminal is connected to a controllable wiper. The variable resistance is provided between the wiper terminal and either one of the other two terminals.
When used to control current, it is called a rheostat. When used to control voltage, it is called a potentiometer.
