27. Resistors & DC Circuits

Which of the following best defines electric current?

Which of the following is the correct SI unit for electric current?

Which type of electric current is typically supplied to household wiring in most homes?

A current of $1.8A$ delivers a charge of $2.5C$. How much time was required?

A circuit consists of a $12 V$ battery connected in series with a $6 \Omega$ resistor. What is the current flowing through the resistor?

In the circuit shown, two batteries with emfs $e_1$ and $e_2$ are connected in series with resistors $R_1$ and $R_2$. If the current flowing through $e_2$ is $i_2$, what is its value?

A sculptor has asked you to help electroplate gold onto a brass statue. You know that the charge carriers in the ionic solution are singly charged gold ions, and you've calculated that you must deposit 0.50 g of gold to reach the necessary thickness. How much current do you need, in mA, to plate the statue in 3.0 hours?

The LHC accelerator at CERN (Switzerland) is designed to carry a 0.58-A beam of protons ( q = 1.6 x 10^-19 C ) traveling at very nearly the speed of light ( 3.0 x 10⁸ m/s) around a ring 27 km in circumference. How many protons are in the beam?

Which of the following best describes the relationship between electric current $I$, charge $Q$, and time $t$ in a conductor?

Why must an electric circuit maintain a closed loop for current to flow?