DC Circuits

Question 1

What is OHMs law?

Answer 1

Ohm’s law describes the relationship between current and voltage for most conductors. If the current through a piece of material at a constant temperature is directly proportional to the voltage across it, then the material is said to obey Ohm’s law. Thus, tripling the voltage (in volts) between two ends of a wire would mean tripling the current (in amperes); the quotient remains constant. The quotient for a given piece of material is called its resistance, , measured in units called ohms.

Question 2

What is Kirchhoff’s first law?

Answer 2

Kirchhoff’s Law states that at any junction in an electrical circuit, the sum of currents flowing towards that point is equal to the sum of currents flowing away from it.

This law can be used to calculate unknown currents at a branching point in an electrical circuit.

Question 3

What is Kirchhoff’s second law?

Answer 3

Kirchhoff’s Voltage Law states that the algebraic sum of all voltages around any in a closed loop is zero. This means that in a circuit the voltage applied is dropped through components, with none left over.

It is important to remember that voltage doesn’t exist at any point but is a difference in potential between two points.

Question 4

Rearrange r=v over i to find voltage

Answer 4

V= I TIMES R

Question 5

Rearrange r=v over i to find current

Answer 5

I = V OVER R