Assertion: Digital signals are continous variations of voltage of curren t.
Reason: Digital signals are essentially single valued functions of time.

Options

A. A and R both are true and R is correct explaination of A
B. A is correct but R is wrong
C. A is wrong but R is true
D. Both are wrong

Explanation

To solve the question regarding the assertion and reason about digital signals, we will analyze each statement step by step.

### Step 1: Analyze the Assertion
The assertion states: "Digital signals are continuous variations of voltage or current."

- **Explanation**: Digital signals are not continuous; they represent discrete values. In digital communication, signals typically take on two distinct levels (often represented as 0 and 1). This means that digital signals do not vary continuously but instead jump between these two states.

### Step 2: Analyze the Reason
The reason states: "Digital signals are essentially single-valued functions of time."

- **Explanation**: This statement is true. Digital signals can be described as functions that take on a single value at any given point in time. For example, at any moment, a digital signal can either be at a high state (1) or a low state (0), but not both simultaneously.

### Step 3: Conclusion
Now, we compare the truth values of the assertion and the reason:
- The assertion is **false** because it incorrectly describes digital signals as continuous.
- The reason is **true** because it correctly states that digital signals are single-valued functions of time.

### Final Answer
The assertion is false, while the reason is true.