A standard carbon resistor has a gold band to indicate + 5% tolerance. If its resistance is 3,500 , what are the upper and lower limits for its resistance? OA . 3495 - 3505 2 OB. 3300 Q - 3600 0 OC. 3325 N - 3675 OD 3450 - 35500
Engineering · College · Mon Jan 18 2021
Answered on
To calculate the upper and lower limits of the resistor's resistance with a tolerance of ±5%, you can apply the following steps:
1. Find out the percentage value of the tolerance: Multiply the given resistance by the percentage of the tolerance. In this case, it's 5% of 3,500 ohms. 5% of 3,500 ohms = 0.05 × 3,500 ohms = 175 ohms
2. Calculate the lower limit of the resistance: Subtract the tolerance value from the nominal value of the resistance to get the lower limit.
Lower limit = 3,500 ohms - 175 ohms = 3,325 ohms
3. Calculate the upper limit of the resistance: Add the tolerance value to the nominal value of the resistance to get the upper limit.
Upper limit = 3,500 ohms + 175 ohms = 3,675 ohms
Thus, the upper and lower limits for the resistor's resistance are 3,325 ohms and 3,675 ohms, respectively. So the correct option is:
OC. 3325 Ω - 3675 Ω
Extra: Tolerance in electrical components like resistors is a measure of how much the actual resistance can vary from the stated or nominal value. It's important because in most circuits, components need to have resistances within certain limits to function properly. Too much variance can result in a circuit not working correctly or even being damaged.
The gold band on a resistor indicates a tolerance of ±5%, which is quite precise but not the most precise available; other tolerance bands include silver (±10%) and no band at all (±20%). For more precision, you might see bands like red (±2%), brown (±1%), or even more precise tolerance levels.
The tolerance is crucial when designing or repairing circuits that require a specific resistance value to ensure proper operation. This characteristic becomes especially crucial in high-precision applications such as timing circuits or analog-to-digital converters, where the resistance value can significantly affect the circuit's functionality.