A semiconducting device is connected in a series circuit with a battery and a resistance.A current is found to pass through the circuit .If the polarity of the battery is reversed, the current drops to almost zero.The device may be

Options

A. An intrinsic semiconductor
B. a p-type semiconductor
C. an n-type semiconductor
D. a p-n junction

Answer

To solve the given problem, we need to analyze the behavior of a semiconducting device when connected in a circuit with a battery and a resistor, particularly focusing on the effect of reversing the battery's polarity.

### Step-by-Step Solution:

1. **Understanding the Circuit**:
- We have a circuit consisting of a battery, a resistor, and a semiconducting device connected in series. The current flows through this circuit when the battery is connected.

2. **Current Flow with Original Polarity**:
- When the battery is connected with a certain polarity (let's say positive terminal to one end of the semiconductor and negative to the other), the current flows through the circuit. This indicates that the semiconductor device is allowing current to pass.

3. **Reversing the Battery Polarity**:
- When the polarity of the battery is reversed, the positive terminal is now connected to the opposite end of the semiconductor device, and the negative terminal is connected to the other end.

4. **Effect on Current**:
- In the case of a semiconductor, particularly a PN junction diode, if the device is forward-biased (positive to P-type and negative to N-type), it conducts current. However, when reverse-biased (positive to N-type and negative to P-type), the current drops to almost zero because the diode prevents current from flowing in the reverse direction.

5. **Identifying the Device**:
- Given that reversing the battery causes the current to drop to almost zero, we can conclude that the semiconducting device in question is likely a PN junction diode. In a PN junction, the current flows when it is forward-biased and stops when it is reverse-biased.

6. **Conclusion**:
- Therefore, the semiconducting device that fits the description provided in the question is a **PN junction diode**.

### Final Answer:
The device may be a **PN junction diode**.

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