Of the diodes shown in the following figures, which one is reverse biased ?

Options

A.
B.
C.
D.

Explanation

To determine which diode is reverse biased among the given options, we need to analyze the connections of the p-n junction diodes to the battery terminals. Here’s a step-by-step solution:

### Step 1: Understand the Basics of Diode Biasing
A diode has two terminals: the p-type (positive) and the n-type (negative). When connected to a battery, the way these terminals are connected determines if the diode is forward biased or reverse biased:
- **Forward Bias**: The p-type terminal is connected to the positive terminal of the battery, and the n-type terminal is connected to the negative terminal.
- **Reverse Bias**: The p-type terminal is connected to the negative terminal of the battery, and the n-type terminal is connected to the positive terminal.

### Step 2: Analyze Each Option
We will analyze each option provided in the figures to see which configuration represents reverse bias.

#### Option A:
- P-type connected to -5V
- N-type connected to -10V

In this case, the p-type is at a higher potential than the n-type (since -5V is greater than -10V). This configuration is **not reverse biased**.

#### Option B:
- P-type connected to ground (0V)
- N-type connected to -10V

Here, the p-type is at 0V (ground) and the n-type is at -10V. The p-type is at a higher potential than the n-type, so this configuration is also **not reverse biased**.

#### Option C:
- P-type connected to 0V (ground)
- N-type connected to +5V

In this configuration, the p-type is at 0V and the n-type is at +5V. The p-type is at a lower potential than the n-type, which means this configuration is **reverse biased**.

### Conclusion
The diode in **Option C** is reverse biased.

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