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Zorluk: KolayOhm's Law Calculations and Concepts

A direct current (DC) heating element is connected to a 120 V120\text{ V} power supply. If an ammeter measures a current of 4 A4\text{ A} flowing through the element, what is its electrical resistance?

  1. A
    480 Ω480\text{ }\Omega
  2. 30 Ω30\text{ }\OmegaCevap
  3. C
    0.033 Ω0.033\text{ }\Omega
  4. D
    116 Ω116\text{ }\Omega

Cevap

30 Ω30\text{ }\Omega
According to Ohm's law, electrical resistance (RR) is defined as the ratio of voltage (VV) across a component to the current (II) passing through it: R=VIR = \frac{V}{I}. Substituting 120 V120\text{ V} and 4 A4\text{ A} gives R=1204=30 ΩR = \frac{120}{4} = 30\text{ }\Omega.

Adım Adım Çözüm

1
Identify the given values and the required quantity
Voltage V=120 VV = 120\text{ V}, Current I=4 AI = 4\text{ A}, Resistance RR is unknown
Establishing the known circuit parameters determines which Ohm's law formula variation to use.
2
Apply Ohm's law rearranged to solve for resistance: R=VIR = \frac{V}{I}
R=120 V4 A=30 ΩR = \frac{120\text{ V}}{4\text{ A}} = 30\text{ }\Omega
Resistance represents the opposition to current flow and is calculated as the ratio of electromotive force to electrical current.

Anahtar Kavram

Ohm's Law Resistance Calculation (R=VIR = \frac{V}{I})
Tahmini Süre:45s
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