The resistance of a discharge tube is

Options

A. zero
B. ohmic
C. non-ohmic
D. infinity

Answer

To solve the question regarding the resistance of a discharge tube, we will follow these steps:

### Step 1: Understand the Concept of Resistance
Resistance (R) in an electrical circuit is defined as the opposition to the flow of electric current. It can be calculated using Ohm's Law, which states that V = IR, where V is the voltage, I is the current, and R is the resistance.

**Hint:** Remember that Ohm's Law applies to ohmic materials where the relationship between voltage and current is linear.

### Step 2: Analyze the Discharge Tube
A discharge tube contains gases, and when a potential difference is applied, it allows the flow of charge from the cathode to the anode. The behavior of the current in such a tube can vary with the applied voltage.

**Hint:** Consider how gases behave under electric fields and how this might affect the current flow.

### Step 3: Examine the V-I Graph
In the case of a discharge tube, we can plot a graph of voltage (V) versus current (I). For ohmic materials, this graph is a straight line, indicating a constant resistance. However, for non-ohmic materials, the graph is nonlinear.

**Hint:** Look for the shape of the graph. A straight line indicates ohmic behavior, while a curve indicates non-ohmic behavior.

### Step 4: Identify the Type of Resistance
Since the V-I curve for the discharge tube is nonlinear, we conclude that the resistance of the discharge tube is non-ohmic. This means that the resistance changes with the applied voltage and current.

**Hint:** Non-ohmic resistance means that the resistance is not constant and varies with the voltage or current.

### Step 5: Conclusion
Based on the analysis, we can conclude that the resistance of the discharge tube is non-ohmic.

**Final Answer:** The resistance of the discharge tube is non-ohmic.