OCR Physics AS Level - Strain gauge, temperature, resistance

[Final Fantasy]

I have an assignment in which I have to design a laboratory experiment (not real, only in theory i.e. planning) to investigate how the resistance of a strain gauge attached to a piece of wood varies with the temperature of the wood.

*IMPORTANT* My teacher said keep it simple, do not over complicate things. Only school lab equipment is allowed. I have to also make predictions, make a graph (temp vs resistance??), and a sample table (prelimanary results).

So far I have come up with stupid ideas like getting a piece of wood, making a hole, sticking a thermometer in it and then place the whole thing in a beaker. Heating up the beaker with bunsen burner (beaker will be on a tripod) and then taking readings off the thermometer. Obviously there is one big problem, where does the strain gauge come in? Do I have to attach it to the wood, if so, then how do I take the readings of the resistance.

I have other ideas such as attaching the strain gauge using glue onto the piece of wood and then some how connecting this in a circuit, but what components would I use, how would I measure the resistance, how to connect it up and heat up the wood and record temperature??

The official question of this planning exercise is: You are required to design a laboratory experiment to investigate how the resistance of a strain gauge attached to a piece of wood varies with the temperature of the wood.

I have just registered on this forum, although I have been a lurker for quite some time now. If all goes well then I'll probably become an active member here.

Basically, I need a step-by-step method/procedure on this if possible. I also got to include a diagram and a possible circuit diagram too? Also have to list the apparatus I'm going to use.


~FF

 

[Final Fantasy]

Bump. EDIT: Does the formula R=pL/A have anything to do with this? Or R=V/I?

Also, I was thinking water baths at different constant temperatures but come to think of it I guess that's not going to work lol.

EDIT: What do you think of this >> Using a power pack, connect ampmeter and strain-gauge-glued-on-wood-with-a-thermometer-in-it, making a circuit. Then heating up the wood with Bunsen burner and recording the temps and resistance.

~FF

 

[Moetasim]

I would approach this experiment by first understanding the principles behind strain gauges and how they measure changes in resistance. Strain gauges are typically made of a thin strip of metal or semiconductor material that changes its resistance when it is stretched or compressed. In this case, the strain gauge will be attached to the piece of wood, and as the wood expands or contracts with temperature changes, it will cause the strain gauge to change its resistance.

To design a simple experiment to investigate this relationship between temperature and resistance, I would suggest the following steps:

1. Materials/Equipment:
- A piece of wood
- A strain gauge
- A thermometer
- A power supply
- A multimeter to measure resistance
- A heat source (e.g. Bunsen burner or hot plate)
- Wires and connectors to build a simple circuit

2. Set up the experiment:
- Attach the strain gauge to the piece of wood using glue or tape.
- Connect the strain gauge to the circuit, making sure to follow the manufacturer's instructions for proper wiring.
- Connect the circuit to the power supply and multimeter.
- Place the thermometer near the strain gauge to measure the temperature of the wood.

3. Take preliminary readings:
- Before heating the wood, take initial readings of the temperature and resistance.
- Record these readings in a table or graph for later comparison.

4. Heat the wood:
- Use the heat source to gradually increase the temperature of the wood.
- Make sure to monitor the temperature with the thermometer and record it at regular intervals.
- As the temperature increases, the resistance of the strain gauge will also change. Record these readings as well.

5. Analyze the data:
- Plot the data in a graph, with temperature on the x-axis and resistance on the y-axis.
- The graph should show a direct relationship between temperature and resistance, with an increase in temperature leading to an increase in resistance.

6. Make predictions:
- Based on the data collected, make predictions about how the resistance will change at different temperatures.
- You can also use mathematical equations or calculations to further analyze the relationship between temperature and resistance.

7. Include diagrams and circuit diagrams:
- In your report, include a labeled diagram of the experimental setup and a circuit diagram of the circuit used to measure resistance.
- These diagrams will help others understand your experiment and how it was conducted.

Overall, this experiment can be easily conducted using basic laboratory equipment and can provide valuable insights into