Table of Contents
- 1 How can you keep the resistance of the circuit the same throughout the experiment?
- 2 How do you control resistance in a circuit?
- 3 What is multimeter precautions?
- 4 What precautions are necessary when measuring circuit characteristics?
- 5 What are some safety precautions when working with electricity?
- 6 How is the resistance of a Circuit determined?
How can you keep the resistance of the circuit the same throughout the experiment?
Dependent Variable is the resistance of the wire. Control Variables are the material, the cross section area and the temperature of the wire. These are kept the same by not changing the wire during the experiment, by keeping the current small and opening the switching between readings.
How do you control resistance in a circuit?
Changing the resistance
- If you increase the number of lamps in a series circuit , there will be less current.
- You could increase or decrease the resistance in a circuit by using a variable resistor .
- The quantities voltage, current and resistance are linked by the relationship :
- This relationship is called Ohm’s Law.
What precautions should be taken in using an electric circuit?
1- Always use insulated tools while working.
- 2-Never use equipment with frayed cords, damaged insulation or broken plugs.
- 3-Know the wire code of your country.
- 4-Never use an aluminium or steel ladder if you are working on any receptacle at height in your home.
- 5-Avoid water at all times when working with electricity.
How can you keep wires at a constant temperature?
One approach is (as discussed above) to keep the wire at a constant temperature by immersing it in a water bath. An alternative would be to use the p.d./current graph above to find the wire’s resistance when no current flows through it, because then there is no heating effect.
What is multimeter precautions?
What are multimeter safety precautions? Before you take a measurement with your multimeter, you should visually inspect it first. Check the meter, test probes and accessories over for signs of physical damage. Make sure all plugs fit securely and keep an eye out for exposed metal or any cracks in the casing.
What precautions are necessary when measuring circuit characteristics?
What are the necessary precautions when measuring current? Always start with the highest range of an ammeter. Deenergize and discharge the circuit completely before you connect or disconnect the ammeter. In dc ammeters, observe the proper circuit polarity to prevent the meter from being damaged.
How do you keep temperature constant in Ohm’s law?
According to Ohm’s law, temperature must remain constant, so[heat] = v×I×t, where time, t, is constant. Therefore, heat is directly proportional to v×I, and you increase v then I will also increase therefore since v and I have increased therefore heat (temperature) will also increase.
Which is the best way to measure resistance?
Turn power to circuit OFF. If a circuit includes a capacitor, discharge the capacitor before taking any resistance reading. 2. Turn digital multimeter dial to resistance, or ohms, which often shares a spot on the dial with one or more other test/measurement modes (continuity, capacitance or diode; see illustration below).
What are some safety precautions when working with electricity?
Never touch or try repairing any electrical equipment or circuits with wet hands. It increases the conductivity of electric current. 2. Never use equipment with frayed cords, damaged insulation or broken plugs.
How is the resistance of a Circuit determined?
To determine the condition of a circuit or component. The higher the resistance, the lower the current flow, and vice versa. In general, the resistance of components used to control circuits (such as switches and relay contacts) starts out very low and increases over time due to factors such as wear and dirt.
How big of a fuse should be used to protect against short circuits?
Normally for protection against short circuits a fuse rated of 150% of the normal circuit current is selected. In the case of a circuit with 10 amperes of current, a 15 ampere fuse will protect against direct short circuits whereas a 9.5 amperes fuse will blow out. 12. Working outside with underground cabling can be dangerous.