Which of the following appliances do not work on the heating effect of current?

Options

A. Geysers
B. Hair dryers
C. Electric bells
D. Electric bulbs

Explanation

To determine which of the following appliances do not work on the heating effect of current, we need to analyze each option provided:

1. **Geysers**: Geysers are appliances that heat water. They work by passing electric current through a heating element, which generates heat and warms the water. Therefore, geysers do work on the heating effect of current.

2. **Hair Dryer**: A hair dryer also operates on the heating effect of current. It uses electric current to heat up a coil, which then blows hot air to dry hair. Thus, hair dryers work on the heating effect of current.

3. **Electric Belt**: Electric belts are used for therapeutic purposes, such as relieving muscle pain. They typically work by generating heat when electric current passes through them. Therefore, electric belts also work on the heating effect of current.

4. **(Repeated Option)**: The question seems to have a repeated option for electric belt, which we have already analyzed.

Since all the options provided (geyser, hair dryer, and electric belt) work on the heating effect of current, we conclude that there is no appliance listed that does not work on this principle.

**Final Answer**: None of the options listed do not work on the heating effect of current; all of them do.

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