The identical loops of copper and aluminium are moving with the same speed in a magnetic field. Which of the following statements true?

Options

A. Induced emf and induced current are same in both loops
B. Induced emf remains same, induced current changes in both loops
C. Induced emf changes but induced current remains same in both loops
D. Induced emf will be more in aluminium loop

Explanation

To solve the problem, we need to analyze the situation of two identical loops made of copper and aluminum moving with the same speed in a magnetic field. We will determine the induced EMF and current in both loops.

### Step-by-Step Solution:

1. **Understanding Induced EMF**:
The induced EMF (Electromotive Force) in a moving conductor in a magnetic field can be calculated using the formula:
\[ \text{EMF} = B \cdot L \cdot V \]
where \( B \) is the magnetic field strength, \( L \) is the length of the conductor, and \( V \) is the velocity of the conductor.

2. **Analyzing the Given Conditions**:
In this case, both loops (copper and aluminum) are identical and are moving with the same speed in the same magnetic field. Therefore, the values of \( B \), \( L \), and \( V \) are the same for both loops.

3. **Calculating Induced EMF**:
Since the formula for EMF does not depend on the material of the loop (copper or aluminum), the induced EMF in both loops will be the same:
\[ \text{EMF}_{\text{copper}} = \text{EMF}_{\text{aluminum}} \]

4. **Understanding Induced Current**:
The induced current \( I \) in a loop can be calculated using Ohm's law:
\[ I = \frac{\text{EMF}}{R} \]
where \( R \) is the resistance of the loop.

5. **Calculating Resistance**:
The resistance \( R \) of a loop is given by:
\[ R = \frac{\rho \cdot L}{A} \]
where \( \rho \) is the resistivity of the material, \( L \) is the length of the loop, and \( A \) is the cross-sectional area. Since copper and aluminum have different resistivities, the resistance of the loops will be different.

6. **Conclusion on Induced Current**:
Since the EMF is the same for both loops but the resistance differs due to the different materials, the induced current will be different:
\[ I_{\text{copper}} \neq I_{\text{aluminum}} \]

7. **Final Answer**:
Therefore, the correct statement is that the induced EMF remains the same, but the induced current changes in both loops. This corresponds to option 2.