What is the current travelling through a cellphone charger when 0.20 mC of electrons pass a point in 0.75 min? Answer in amperes and microamperes (μA).

How long does it take electrons to get from a car battery to the starting motor? Assume the current is 320A and the electrons travel through a copper wire with cross-sectional area 0.120 cm2 and length 0.840 m. The number of charge carriers per unit volume is 8.49 x 1028 m3. Number i 428.5 Unit m/s

The resistance of the skin on a person's finger is typically about 37,000 N. How much voltage would be needed to cause a current of 0.001 A to flow into the finger? (This is about enough current to just be felt by most people.) V

Suppose you have a rod of pure silicon with a diameter of 2.79cm and a length of 20.6cm. These rods are often used in experiments, such as the Large Hadron Collider in France/Switzerland to detect high-energy particles, and they have a very high resistivity of 2300Ω⋅m. What current, in amperes, flows through the rod when a potential difference of 1.23* 10^3 V is applied between its ends ?

A capacitor of capacitance C = 1 µF is connected in series to a resistor of resistance R = 10 MN and a battery of emf = 3V. The capacitor is initially discharged. How many %3D seconds will it take for the current in the circuit to decrease to 42% of its initial value? Write the answer, rounded off to 2 decimal places, without units.

Useful Constants: k = 9.00 × 10º Nm² C2 8.85 x 10-12 C² Nm2 %3D e = 1.6 x 10-19 C me = 9.11 x 10 mp = 1.67 × 10-27kg %3D -27 mn = 1.68 x 10 %3D

(1) What is a definition of electric current? Label the variables. (2) Suppose that 1016 electrons pass through a cross-section of a wire each second. What is the current in the wire? (3) The current in a wire varies with time according to the relation / = 5+3t where I is in amperes andt is in seconds. What is the number of coulombs of charge that pass a cross section of the wire between t=3s and t=5s?

The voltage across a 2.5-µF capacitor in a copying machine is zero. What is the voltage after 15 ms if a current of 25 mA charges the capacitor? The voltage at t = 15 ms is V. (Type an integer or a decimal.)

A lightning bolt has a total charge of 40 C. If it takes 0.5 s to travel to the ground what is the current?

An unmarked battery has an unknown internal resistance. If the battery is connected to a fresh 5.60-V battery (negligible internal resistance) positive to positive and negative to negative, the current through the circuit is 10.0 mA. If the polarity of the unknown battery is reversed, the current increases to 25.0 mA. Determine the source voltage and internal resistance of the unknown battery. Assume that in each case the direction of the current is negative to positive in the 5.60-V battery.