- #1
franklinear
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The meter in the circuit shown in the image has an uncalibrated linear scale. With the circuit as shown, the scale reading is 20. Find the scale reading when another 2000Ω resistor is connected across XY.
vk6kro said:Work out the currents for each setup. Initially, all components are in series.
1) 1.5 volts / ( 3000 ohms + 2000 ohms) =
Now, 2000 ohms in parallel with 2000 ohms = 1000 ohms.
2) 1.5 volts / ( 3000 ohms + 1000 ohms ) =
Then, if the first current = "20" on the linear scale, what does the second current read?
It will read more, won't it?
vk6kro said:No.
Work out the two values with your calculator.
What does this equal:
1) 1.5 volts / ( 3000 ohms + 2000 ohms) =
Add 3000 and 2000 and divide 1.5 by this total.
What does this equal:
2) 1.5 volts / ( 3000 ohms + 1000 ohms ) =
Add 3000 and 1000 and divide 1.5 by this total.
You should get two currents in Amps.
Now the meter reading will be 20 times the ratio of (current 2 / current 1)
I agree with your answer but I don't think you know how you got it.
This is clearly course work, so we can't just do it for you.
elbeasto said:Hey vk6kro, is the total resistance of parallel resistors equal to the highest resistance resistor divided by the number of resistors in parallel?
I am not a physics major or anything but I do like to toy around with equations. I am sure this is a basic question in your realm.
vk6kro said:Another way of getting the total of resistors in parallel, especially if they are not the same, is this:
Rtotal = R1 * R2 / (R1 + R2)
To determine the scale reading with a new resistor in a circuit, you will need to use Ohm's Law, which states that the voltage across a resistor is directly proportional to the current flowing through it. By measuring the voltage and current in the circuit, you can use the formula V=IR to calculate the resistance of the new resistor. This resistance value will then be used to determine the scale reading on the circuit.
To find the scale reading with a new resistor in a circuit, you will need a voltmeter, an ammeter, and the new resistor. The voltmeter will measure the voltage across the resistor, and the ammeter will measure the current flowing through it. These measurements will then be used to calculate the resistance of the new resistor.
Yes, any resistor can be used in a circuit to find the scale reading as long as it is properly connected in the circuit and its value is known. However, it is important to note that the resistance of the new resistor should be within the range of the scale reading for accurate results.
It is important to find the scale reading with a new resistor in a circuit because it allows you to measure the resistance of the resistor and ensure that it is within the desired range for the circuit. This information is crucial for proper functioning of the circuit and to prevent any potential damage.
If the scale reading does not match the expected value, you should double check your measurements and calculations to ensure accuracy. If everything appears to be correct, it is possible that the new resistor is defective or has a different resistance value than stated. In this case, you may need to replace the resistor or adjust your circuit accordingly.