estimate the value of resistances needed to make a variable timer for intermittent windshield wipers: one wipe every 15 s, 8 s, 4 s, 2 s, 1 s. assume the capacitor used is on the order of 3 μf .

Resistance is encountered by an electron as it passes through the external circuit's wires and loads. The obstacle to the flow of charge is called resistance. An electron cannot travel in a straight line from one terminal to the next. Instead, a zigzag path is created by several collisions with stationary atoms in the conducting substance. The movement of the electrons is hampered by resistance. Resistance prevents the passage of charge, whereas the electric potential difference between the two terminals promotes it. The combined influence of these two factors determines the rate at which charge flows from terminal to terminal.

Calculations:

θ = R * C

15s --- R = θ / C = 15 / 3x 10^-6 = 5x 10^6Ω----- 5000 kΩ

8s------R = 8 / 3x 10^-6 = 2.7x 10^6 Ω ----------------2700 kΩ

4s------R = 4 / 3x 10^-6 = 1.3x10^6 Ω -------------------1300kΩ

2s------R = 2 /3x 10^-6 = 0.67x 10^6 Ω ------------------670 kΩ

1s -----R = 1 / 3x10^-6 = 0.33x 10^6 Ω---------------------------330 kΩ

Part A

Answer : 330 kΩ ( min)

Part B

Answer: 5000 kΩ (max)

To learn more about resistance,visit:

https://brainly.com/question/11431009

#SPJ4