Table of Contents
- 1 How can the range of each ohmmeter be changed?
- 2 What is the importance of interpreting resistance of an ohmmeter?
- 3 How do you choose the ohmmeter range to be used when measuring resistance values?
- 4 What is the range that determines the good working value of a resistor?
- 5 How do variable resistors work?
How can the range of each ohmmeter be changed?
Shunt resistors are needed to provide multiple ranges on the ohmmeter to measure a range of resistance values from the very small to very large. For each range, a different value of shunt resistance is switched in.
What is the function of the adjustable resistor in an ohmmeter?
The function of the variable and the fixed resistors are to ensure that the ohmmeter on its own has just enough resistance such that the current is just big enough to cause maximum deflection of the needle. And once this is achieved, we can say that the ohmmeter has been calibrated.
What is the importance of interpreting resistance of an ohmmeter?
The purpose of an ohmmeter, of course, is to measure the resistance placed between its leads. This resistance reading is indicated through a mechanical meter movement which operates on electric current.
Why do we use variable resistance?
Variable resistors are widely used in electric circuits to adjust the value of current or voltage, since the resistance of variable resistors can be set to a certain value. Variable resistors allow you to adjust the value of voltage by changing the resistance and keeping current constant .
How do you choose the ohmmeter range to be used when measuring resistance values?
Set your multimeter to the highest resistance range available. The resistance function is usually denoted by the unit symbol for resistance: the Greek letter omega (Ω), or sometimes by the word “ohms.” Touch the two test probes of your meter together. When you do, the meter should register 0 ohms of resistance.
What is the ideal range of ohmmeter when measuring high resistance?
A good rule is to use a range in which the reading obtained does not exceed ten times, or is not less than one-tenth, the mid scale reading. The useful range of the scale shown is, by this rule, from 450 ohms to 45,000 ohms. Most ohmmeters have more than one scale.
What is the range that determines the good working value of a resistor?
Typical resistor tolerances for film resistors range from 1\% to 10\% while carbon resistors have tolerances up to 20\%. Resistors with tolerances lower than 2\% are called precision resistors with the or lower tolerance resistors being more expensive.
How do you indicate the resistance reading of an ohmmeter?
How do variable resistors work?
A variable resistor works by adjusting the path that current has to flow. The dial you turn will move another piece of wire inside the resistor. The end result is that the electricity will travel through a certain length of the strip depending on where you turn the knob.
What is the main function of ohmmeter?
ohmmeter, instrument for measuring electrical resistance, which is expressed in ohms. In the simplest ohmmeters, the resistance to be measured may be connected to the instrument in parallel or in series. If in parallel (parallel ohmmeter), the instrument will draw more current as resistance increases.