For amplification by a triode, the signal to be amplified is given to

Options

A. the cathode
B. the grid
C. the glass-envelope
D. the anode

Answer

To solve the question regarding where the signal to be amplified is given in a triode, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components of a Triode**:
A triode consists of three main components: the cathode, the anode (or plate), and the grid. Each of these components plays a specific role in the functioning of the triode.

2. **Identify the Function of Each Component**:
- **Cathode**: This is the electrode that emits electrons when heated. It is not where the input signal is applied.
- **Anode**: This is the electrode that collects the electrons emitted by the cathode. It is responsible for the output current but does not receive the input signal.
- **Grid**: This is a control electrode placed between the cathode and anode. It regulates the flow of electrons from the cathode to the anode.

3. **Determine Where the Input Signal is Applied**:
The input signal that needs to be amplified is applied to the grid. The grid voltage can control the amount of current flowing from the cathode to the anode. A small change in the grid voltage results in a significant change in the plate current, which is the principle behind amplification in a triode.

4. **Conclusion**:
Therefore, for amplification by a triode, the signal to be amplified is given to the **grid**.

### Final Answer:
The signal to be amplified is given to the **grid**.

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