Assertion : If the wavelength `lamda` of photon and de Broglie wavelength of electron are same , their energy is also same.
Reason : Momentum of both the particles is same by de Broglie hypothesis.

Options

A. If both assertion and reason are correct and reason is a correct explanation of the assertion.
B. If both assertion and reason are correct but reason is not the correct explanation of assertion.
C. If assertion is correct but reason is incorrect
D. If assertion is incorrect but reason is correct.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that if the wavelength \( \lambda \) of a photon and the de Broglie wavelength of an electron are the same, then their energy is also the same.

- The energy of a photon is given by the formula:
\[ E_{photon} = \frac{hc}{\lambda} \]
where \( h \) is Planck's constant and \( c \) is the speed of light.

- The energy of an electron, using its de Broglie wavelength, is given by:
\[ E_{electron} = \frac{h^2}{2m\lambda^2} \]
where \( m \) is the mass of the electron.

### Step 2: Compare the Energies
Now, we need to check if these two energies are equal when \( \lambda \) is the same for both:

1. For the photon:
\[ E_{photon} = \frac{hc}{\lambda} \]

2. For the electron:
\[ E_{electron} = \frac{h^2}{2m\lambda^2} \]

Clearly, the two expressions are not equal. Thus, the assertion is **false**.

### Step 3: Analyze the Reason
The reason states that the momentum of both particles is the same by the de Broglie hypothesis.

- The momentum \( p \) of a photon is given by:
\[ p_{photon} = \frac{E_{photon}}{c} = \frac{h}{\lambda} \]

- The momentum of an electron, using its de Broglie wavelength, is given by:
\[ p_{electron} = mv = \frac{h}{\lambda} \]
where \( v \) is the velocity of the electron.

Since both momenta are equal when the wavelengths are the same, the reason is **true**.

### Conclusion
- The assertion is **false**.
- The reason is **true**.
- Therefore, the correct answer is (D): Assertion is false, Reason is true.