1. A calculator draws 15 mA of current from a solar cell for 25 s. Calculate the total charge. 2. How many electrons are passing through the calculator in #1 each second? 3. A light bulb draws a current of 0.6 A. If the bulb is left on for 8.0 min.how many electrons pass through the bulb?

1. **Charge Calculation:**<br /><br />* **Formula:** Charge (Q) = Current (I) * Time (t)<br />* **Given:** Current (I) = 15 mA = 0.015 A, Time (t) = 25 s<br />* **Calculation:** Q = 0.015 A * 25 s = 0.375 Coulombs (C)<br /><br />**Answer:** The total charge is 0.375 C.<br /><br /><br />2. **Electron Flow Rate:**<br /><br />* **Formula:** Current (I) = Charge (Q) / Time (t) and Charge (Q) = Number of electrons (n) * Elementary Charge (e)<br />* **Given:** Current (I) = 15 mA = 0.015 A, Elementary Charge (e) = 1.6 x 10^-19 C<br />* **Calculation:** First, find the charge passing per second: Since current is already given as the charge per second (Amperes = Coulombs/second), we have Q = 0.015 C per second.<br />Then, find the number of electrons: n = Q / e = (0.015 C) / (1.6 x 10^-19 C/electron) = 9.375 x 10^16 electrons<br /><br />**Answer:** Approximately 9.375 x 10^16 electrons pass through the calculator each second.<br /><br /><br />3. **Total Electron Count:**<br /><br />* **Formula:** Charge (Q) = Current (I) * Time (t) and Charge (Q) = Number of electrons (n) * Elementary Charge (e)<br />* **Given:** Current (I) = 0.6 A, Time (t) = 8.0 min = 480 s, Elementary Charge (e) = 1.6 x 10^-19 C<br />* **Calculation:**<br />First, calculate the total charge: Q = I * t = 0.6 A * 480 s = 288 C<br />Then, calculate the number of electrons: n = Q / e = 288 C / (1.6 x 10^-19 C/electron) = 1.8 x 10^21 electrons<br /><br />**Answer:** 1.8 x 10^21 electrons pass through the bulb.<br />