2. Variable resistors are also known as: A. Fixed resistors B. Potentiometers C. Thermistors D. Photoresistors Answer: B. Potentiometers
3. A thermistor is a type of resistor whose resistance: A. Decreases with temperature B. Increases with temperature C. Depends on the material D. Can either increase or decrease with temperature Answer: D. Can either increase or decrease with temperature
4. Which type of resistor is commonly used for high-precision applications? A. Carbon film resistor B. Wire-wound resistor C. Metal film resistor D. Variable resistor Answer: C. Metal film resistor
5. Light-dependent resistors (LDRs) are primarily used in: A. High-voltage circuits B. Light-sensitive circuits C. Temperature control systems D. Motor speed control Answer: B. Light-sensitive circuits
Resistor Color Coding
6. In the resistor color code, the color red represents the value: A. 1 B. 2 C. 3 D. 4 Answer: B. 27. A resistor has color bands: Brown, Black, Red, and Gold. Its resistance is: A. 1 kΩ±5%1 \, \text{k}\Omega \pm 5\% B. 10 kΩ±5%10 \, \text{k}\Omega \pm 5\% C. 1.2 kΩ±5%1.2 \, \text{k}\Omega \pm 5\% D. 100 kΩ±5%100 \, \text{k}\Omega \pm 5\% Answer: A. 1 kΩ±5%1 \, \text{k}\Omega \pm 5\%
8. In a resistor color code, the multiplier is represented by the third band. What does the color green indicate for the multiplier? A. 10310^3 B. 10510^5 C. 10610^6 D. 10910^9 Answer: B. 10510^5
9. A resistor has color bands: Yellow, Violet, Orange, and Silver. Its resistance is: A. 47 kΩ±10%47 \, \text{k}\Omega \pm 10\% B. 4.7 kΩ±10%4.7 \, \text{k}\Omega \pm 10\% C. 470 kΩ±10%470 \, \text{k}\Omega \pm 10\% D. 47 \, \text{\(\Omega} \pm 10% ) Answer: A. 47 kΩ±10%47 \, \text{k}\Omega \pm 10\%
10. What does the fourth band in a 4-band resistor indicate? A. Resistance value B. Multiplier C. Tolerance D. Power rating Answer: C. Tolerance
Applications of Resistors
11. Resistors are used in electronic circuits to: A. Store charge B. Control current C. Convert AC to DC D. Increase power Answer: B. Control current12. Which of the following is an application of a variable resistor? A. Voltage dividers B. Speed control in fans C. Light dimming D. All of the above Answer: D. All of the above
13. In a voltage divider circuit, the function of resistors is to: A. Decrease voltage to a required level B. Increase the current C. Block alternating current D. Amplify signals Answer: A. Decrease voltage to a required level
14. Power resistors are commonly used in: A. High-frequency circuits B. Current limiting applications C. Low-power signal circuits D. Battery-powered devices Answer: B. Current limiting applications
15. The main role of resistors in LED circuits is to: A. Increase brightness B. Prevent overheating of LEDs C. Limit current through the LEDs D. Change LED color Answer: C. Limit current through the LEDs