Table of Contents
- 1 How do you find the maximum current through a resistor?
- 2 How does adding resistors affect current?
- 3 How do you limit voltage in a circuit?
- 4 How does the resistance of a material determine how much electric current flows through it?
- 5 How is the voltage across a series of resistors determined?
- 6 What should the resistive value of a pull up resistor be?
How do you find the maximum current through a resistor?
( in reality a resistor’s watt rating is given a 10-20% margin I believe). If you divide 8.366V by 140 ohms you get 59.76 mA which the maximum current the resistor can handle.
How does adding resistors affect current?
The current after a resistor is the exact same as it was before the resistor. If you now add a resistor in series into this circuit – the current of the circuit will be smaller. So yes, the resistor does reduce the current. (But the current flowing into the resistor is still the same as the current flowing out.)
How does the resistance of a circuit element depend on its material and geometry?
The longer the cylinder, the greater its resistance. The larger its cross-sectional area A, the smaller its resistance. As mentioned, for a given shape, the resistance depends on the material of which the object is composed. Different materials offer different resistance to the flow of charge.
How do you find the maximum current value?
Calculate the resistance from the average power and the rms voltage using equation 21-6. Then, from the resistance and rms voltage, solve for the rms current using Ohm’s Law (equation 21-2). Convert the rms current to maximum current by multiplying it by the square root of two.
How do you limit voltage in a circuit?
This type of circuit is called a voltage divider, and is a common way to reduce voltage in a circuit.
- When the two resistors in the voltage divider are of the same value, the voltage is cut in half.
- For example, suppose you’re using a 9 V battery, but your circuit requires 6 V.
How does the resistance of a material determine how much electric current flows through it?
Factors That Affect Resistance All materials have some resistance, but certain materials resist the flow of electric current more or less than other materials do. In a similar way, more current can flow through a wide wire than a narrow wire. A longer wire has more resistance than a shorter wire.
How to calculate the maximum current in a circuit?
This question is unanswerable without knowing the specifications of the resistor. The resistor specification will indicate the value of the resistance and the maximum power dissipation of the resistor. Then you can use the basic equation P = I 2 R to work out the maximum current.
What is the maximum current allowed in a resistor?
In other words the maximum current allowed is the square root of the ratio between the resistor’s power rating and worst case resistance. So for example if we have a 1k [math]\\Omega [/math] ¼Watt 5% tolerance resistor then the maximum resistance in tolerance would be 1050 [math]\\Omega [/math] and so the maximum current is: which is 15mA.
How is the voltage across a series of resistors determined?
Series Resistor Voltage The voltage across each resistor connected in series follows different rules to that of the series current. We know from the above circuit that the total supply voltage across the resistors is equal to the sum of the potential differences across R 1, R 2 and R 3, VAB = VR1 + VR2 + VR3 = 9V.
What should the resistive value of a pull up resistor be?
Reducing the resistive value further, will produce a smaller voltage drop but increase the current. Then we can see that while there may be a maximum allowable resistive value, the resistance value for pull-up resistors is not usually that critical with resistance values ranging from between 10k to 100k ohms acceptable.