Which of the following concepts has no contributions by Einstein ?

Options

A. General Theory of relativity
B. Photoelectric effect
C. Quantum model of hydrogen atom
D. Quantum theory

Explanation

To determine which concept has no contributions by Einstein, let's analyze the options provided in the question step by step.

### Step 1: Identify the Concepts
We have four concepts to evaluate:
1. General Theory of Relativity
2. Special Theory of Relativity
3. Photoelectric Effect
4. Quantum Model of Hydrogen Atom

### Step 2: Analyze Each Concept
1. **General Theory of Relativity**: This theory was developed by Einstein and describes how gravity affects the fabric of space-time. It is a significant contribution to physics.

2. **Special Theory of Relativity**: This is another major contribution by Einstein. It introduced concepts such as the relativity of time and space and the famous equation \(E=mc^2\).

3. **Photoelectric Effect**: Einstein explained the photoelectric effect, which describes how light can eject electrons from a material. His work on this phenomenon earned him the Nobel Prize in Physics.

4. **Quantum Model of Hydrogen Atom**: This model was primarily developed by Niels Bohr, who corrected many of the mistakes in Rutherford's model of the atom. While Einstein contributed to quantum theory, he did not specifically develop the quantum model of the hydrogen atom.

### Step 3: Conclusion
Based on the analysis:
- The concepts that Einstein contributed to are the General Theory of Relativity, Special Theory of Relativity, and the Photoelectric Effect.
- The Quantum Model of Hydrogen Atom was developed by Niels Bohr, indicating that this concept has no contributions from Einstein.

Thus, the answer to the question is the **Quantum Model of Hydrogen Atom**.

### Final Answer
**C. Quantum Model of Hydrogen Atom**

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