A uniformly conducting wire is bent to form a ring of mass `'m'` and radius `'r'`, and the ring is placed on a rough horizontal surface with its plane horizontal. There exists a uniform and constant horizontal magnetic field of induction `B`. Now a charge `q` is passed through the ring in a very small time interval `Deltat`. As a result the ring ultimately just becomes vertical. Calculate the value of `g`(acceleration due to gravity) in terms of other given quantities. Assume that friction is sufficient to prevent slipping and ignore any loss in energy.

Explanation

To solve the problem, we will analyze the dynamics of the conducting ring when a charge is passed through it in a magnetic field. We will derive the expression for the acceleration due to gravity \( g \) in terms of the other given quantities.

### Step-by-step Solution:

1. **Understanding the System**:
- We have a conducting ring of mass \( m \) and radius \( r \) placed on a rough horizontal surface.
- A uniform magnetic field \( B \) is present, and a charge \( q \) is passed through the ring in a very short time interval \( \Delta t \).
- The ring initially lies flat (horizontal) and then rotates to become vertical.
...