Physics

Question

If a lamp has a resistance of 136 ohms when it operates at a power of 1.00 × ^2, what is the potential difference across the lamp?

1 Answer

  • Given resistance in ohms and current in ampere, the power can be calculated by the equation,
                                          P = I² x R
    where I is current, P is power, and R is resistance
    Substituting the given values,
                                1.00 x 10² = (I²) x 136 ohms ;   I = 0.8575 amp
    Then, by Ohm's law, the value of V = I x R. Substituting,
                                           V = (0.8575 amp) x (136 ohms) = 116.619 volts
    Thus, the potential difference across the lamp is approximately equal to 116.619 volts. 
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