19. The formula for electrical power, [tex]P[/tex], is [tex]P = I^2 R[/tex], where [tex]I[/tex] is current and [tex]R[/tex] is resistance. The formula for [tex]I[/tex] in terms of [tex]P[/tex] and [tex]R[/tex] is:

1. [tex]I = \left(\frac{P}{R}\right)^2[/tex]
2. [tex]I = \sqrt{\frac{P}{R}}[/tex]
3. [tex]I = (P - R)^2[/tex]
4. [tex]I = \sqrt{P - R}[/tex]



Answer :

To find the formula for the current [tex]\( I \)[/tex] in terms of the power [tex]\( P \)[/tex] and resistance [tex]\( R \)[/tex], we can start from the given formula for electrical power:

[tex]\[ P = I^2 R \][/tex]

We need to express [tex]\( I \)[/tex] in terms of [tex]\( P \)[/tex] and [tex]\( R \)[/tex]. Follow these steps:

1. Start from the given formula:
[tex]\[ P = I^2 R \][/tex]

2. Isolate [tex]\( I^2 \)[/tex]:
To solve for [tex]\( I^2 \)[/tex], divide both sides of the equation by [tex]\( R \)[/tex]:
[tex]\[ \frac{P}{R} = I^2 \][/tex]

3. Solve for [tex]\( I \)[/tex]:
To isolate [tex]\( I \)[/tex], take the square root of both sides:
[tex]\[ I = \sqrt{\frac{P}{R}} \][/tex]

Thus, the correct formula for [tex]\( I \)[/tex] in terms of [tex]\( P \)[/tex] and [tex]\( R \)[/tex] is:
[tex]\[ I = \sqrt{\frac{P}{R}} \][/tex]

Therefore, the correct choice from the given options is:

2) [tex]\( I = \sqrt{\frac{P}{R}} \)[/tex]