# Homework Help: Factors determining the sensitivity of a galvanometer

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1. Jun 10, 2017

1. The problem statement, all variables and given/known data
A galvanometer is connected to a solenoid, and there is a magnet bar entering the solenoid to induce an emf. What factors determine the displacement of the pointer of the galvanometer?

2. Relevant equations
emf (induced) = -N ΔΦ/ Δt
sensitivity of the galvanometer = θ/i
3. The attempt at a solution

That might be an easy question, but my text book doesn't give me the answer and I would like to make sure of my solution.
When I read the question I though in various factor:
1. The rate of change of magnetic flux.
2. The number of turns of the solenoid.
3. The resistance of the solenoid.
4. The sensitivity of the galvanometer.
I just don't know how to pick the suitable factors to put in my exam, and the most convenient ones for the case mentioned above, i.e. a magnetic bar entering the solenoid to induce an emf.
So what is the best answer to the question?

2. Jun 10, 2017

### cnh1995

Or the speed of the magnet. It is measurable.
..and the resistance of the galvanometer.

3. Jun 10, 2017

All of them are appropriate?

4. Jun 10, 2017

### rude man

You could add the direction of the magnet's motion. Which direction will the galvanometer deflect if the magnet is (1) pushed in, and (2) pulled out? What about the direction of leaving the solenoid in each directon?

Last edited: Jun 10, 2017
5. Jun 10, 2017

### cnh1995

Yes.
Or the inductance of the solenoid. It includes all the physical parameters like number of turns, area, length, permeability etc.