Fundamental unit out of the following is

Options

A. ampere
B. newton
C. ohm
D. Weber

Answer

To determine the fundamental unit from the given options, we need to understand what a fundamental unit is. Fundamental units are the basic units of measurement from which other units are derived. There are seven fundamental quantities in the International System of Units (SI), which include:

1. Length (meter, m)
2. Mass (kilogram, kg)
3. Time (second, s)
4. Electric current (ampere, A)
5. Temperature (kelvin, K)
6. Amount of substance (mole, mol)
7. Luminous intensity (candela, cd)

Now, let's analyze the options provided in the question:

1. **Newton (N)**: This is a derived unit for force. It is defined as kg·m/s² (kilogram meter per second squared), which means it is not a fundamental unit.

2. **Ohm (Ω)**: This is a derived unit for electrical resistance. It can be expressed in terms of other units as V/A (voltage per ampere), which also makes it a derived unit.

3. **Weber (Wb)**: This is a derived unit for magnetic flux. It can be expressed in terms of other units such as V·s (volt second), indicating it is also a derived unit.

4. **Ampere (A)**: This is the unit of electric current and is one of the seven fundamental units in the SI system.

Based on this analysis, the only fundamental unit among the options is **Ampere (A)**.

### Final Answer:
The fundamental unit out of the following is **Ampere (A)**.