Experiments

Experiments

1. Electrical investgations

   • Precautions
     • 1. check for clean connection
     • 2. check for zero error
     • 3. switch off the current when not taking a measurement
     • 4. when measuring resistance use low current and voltage to avoid heating and changing resistance
   • Improvements
     • 1, minimize the current
     • 2. turn down power supply
     • 3. increase resistance
     • 4. switch off between readings
   • Safety
     • 1. do not touch live wires
     • 2. checked circuit connections are clean
     • 3. switch off the power supply while changing components to avoid electric shocks
     • 4. wear safety googles

2. Thermal investigations

   • Control variables
     • 1. same initial temperature
     • 2. same volume of water
     • 3. same time intervals
   • Reliable readings
     • 1. stir before reading
     • 2. keep thermometer at the same depth
     • 3. wait until thermometer reading stop rising
   • Accuracy
     • 1. add insulation
     • 2. keep constant room temperature
     • 3. avoid loss of heat