Which of the following instruments use magnet?

Options

A. Tape recorders
B. ATM cards
C. Microphones
D. All of these

Explanation

To determine which instruments use magnets, we can analyze each option provided. Here’s a step-by-step solution:

### Step 1: Identify the Instruments
List the instruments mentioned in the question. The instruments are:
- Tape recorder
- ATM card
- Microphone

### Step 2: Understand How Each Instrument Uses Magnets
- **Tape Recorder**: Tape recorders use magnets to record and play back sound. They have magnetic tape that stores audio signals.
- **ATM Card**: ATM cards have a magnetic strip on the back. This strip contains information that can be read by ATM machines, which rely on magnetic technology.
- **Microphone**: Many microphones use magnets to convert sound waves into electrical signals. They often have a diaphragm that moves in the presence of sound, interacting with a magnet to create sound waves.

### Step 3: Conclusion
Since all three instruments (tape recorder, ATM card, and microphone) utilize magnets in their operation, we can conclude that they all use magnets.

### Final Answer
All of the above instruments (tape recorder, ATM card, and microphone) use magnets.

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