Question

1. what is the unit of electrical resistance?
2. which equation correctly links voltage e, current i and resistance r?

e = i x r
e = i ÷ r
e = r ÷ i

1. a current of 0.5 a flows through a 22 ω resistor. what is the value of the voltage across it?
2. which equation correctly links electric power p, voltage e and current i?

p = e x i
p = i ÷ e
p = e ÷ i

Explanation:

Step1: Recall unit of resistance

The unit of electrical resistance is the ohm, symbol $\Omega$.

Step2: Recall Ohm's law

Ohm's law states that $E = I\times R$.

Step3: Calculate voltage using Ohm's law

Given $I = 0.5A$ and $R=22\Omega$, using $E = I\times R$, we have $E=0.5\times22 = 11V$.

Step4: Recall power - voltage - current relation

The correct equation for electric power is $P = E\times I$.

Answer:

1. Ohm ($\Omega$)
2. $E = I\times R$
3. $11V$
4. $P = E\times I$