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Grade 12th passElectromagnetic Induction

A geyser is operated from 230v 50c/s main. The freequency of instantaneous power consumed by the geyser is

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9 Years agoGrade 12th pass
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ApprovedApproved Tutor Answer1 Year ago

To determine the frequency of instantaneous power consumed by a geyser operating on a 230V, 50Hz mains supply, we need to understand a few key concepts about electrical power and how it relates to frequency.

Understanding Electrical Power and Frequency

Electrical power is the rate at which electrical energy is transferred by an electric circuit. The frequency, measured in hertz (Hz), indicates how many cycles per second an alternating current (AC) completes. In your case, the geyser operates on a 50Hz supply, which means the current alternates direction 50 times every second.

Instantaneous Power Calculation

Instantaneous power can be calculated using the formula:

  • P(t) = V(t) × I(t)

Where:

  • P(t) is the instantaneous power at time t.
  • V(t) is the instantaneous voltage at time t.
  • I(t) is the instantaneous current at time t.

For a geyser connected to a 230V AC supply, the voltage can be expressed as:

  • V(t) = Vmax × sin(ωt)

Here, Vmax is the peak voltage, and ω (omega) is the angular frequency, which can be calculated as:

  • ω = 2πf

Given that the frequency (f) is 50Hz, we can calculate:

  • ω = 2π × 50 = 100π rad/s

Peak Voltage Calculation

The peak voltage (Vmax) for a 230V RMS (Root Mean Square) supply can be calculated as:

  • Vmax = Vrms × √2 ≈ 230 × 1.414 ≈ 325.27V

Current Consideration

The current (I) will also vary with time, depending on the resistance of the geyser's heating element. Assuming the geyser has a resistive load, the current can be expressed similarly:

  • I(t) = Imax × sin(ωt)

Where Imax is the peak current, which can be calculated using Ohm's Law:

  • Imax = Vmax / R

Frequency of Instantaneous Power

Now, the instantaneous power can be expressed as:

  • P(t) = Vmax × sin(ωt) × Imax × sin(ωt)

Using the trigonometric identity for the product of sines, we can simplify this to:

  • P(t) = 0.5 × Vmax × Imax × (1 - cos(2ωt))

This shows that the instantaneous power oscillates at a frequency of 2f, which is double the supply frequency. Therefore, for a geyser operating on a 50Hz supply, the frequency of the instantaneous power consumed is:

  • 2 × 50Hz = 100Hz

Summary

In summary, while the geyser operates on a 230V, 50Hz mains supply, the frequency of the instantaneous power consumed by the geyser is 100Hz. This is a result of the nature of AC power and how voltage and current interact over time.