6 d electronics 221110

659 views

Published on

Introduction to electricity - Higher physics.
Measuring current, voltage, series and parallel circuits

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
659
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
22
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

6 d electronics 221110

  1. 1. Electricity 6D: Monday 22nd November
  2. 2. Measuring current • Current (flow of charge) has symbol I, and is measured in Amperes or Amps (A) for short • We use an Ammeter to measure current through a circuit • Ammeter is connected in line with the other components – in series – We ‘break into’ the circuit:
  3. 3. Voltage • Voltage (or potential difference) has symbol V, and is measured in Volts (V) • Voltage tells us how much energy is transferred by a component in a circuit: – A voltage of 1V means 1 Joule (J) of electrical energy is being transferred into other forms every time 1 Coulomb (C) of charge passes through a component • 1 Volt = 1 Joule per Coulomb OR 1V = 1JC-1
  4. 4. Measuring voltage • We use an Voltmeter to measure voltage across a component: Vsupply Vlamp Ilamp
  5. 5. Experiments: • Aim: Measuring current and voltage in a series circuit • Working in pairs: – Collect 3 cells, 4 lamps, 10 wires, 1 Ammeter and 1 Voltmeter • A) Measure the current in the circuit for 1, 2, 3 and 4 bulbs • B) Measure the current at different points within our circuit containing 4 bulbs, and the voltage across all 4 bulbs • Write down your results in a table
  6. 6. Series circuits: Conclusions • When more bulbs are added to the series circuit the current is reduced • The current is the same at ALL points within the series circuit: • Isupply = I1 = I2 = I3 = … • The voltage of the supply is equal to the sum of the voltages across all the components in the circuit: • Vsupply = V1 + V2 + V3 + …
  7. 7. Parallel circuits • In a parallel circuit, current has more than one path in which to flow around the circuit: Vsupply I1 I2 I3 V1 V2 V3 Isupply
  8. 8. Experiment • Aim: Measuring current and voltage in a parallel circuit • Set up parallel circuit as shown • Measure the voltage across the cells (Vsupply) and the voltage across each lamp (V1, V2, V3, V4) • Measure the current through each lamp (I1, I2, I3, I4) and the current drawn from the supply, Isupply
  9. 9. Parallel circuits: Conclusions • The sum of all currents in the parallel branches in the circuit is equal to the current drawn from the supply: • Isupply = I1 + I2 + I3 + … • The voltage across components in parallel are the same and equal to the supply voltage • Vsupply = V1 = V2 = V3 = …
  10. 10. Parallel circuits: Conclusions • The sum of all currents in the parallel branches in the circuit is equal to the current drawn from the supply: • Isupply = I1 + I2 + I3 + … • The voltage across components in parallel are the same and equal to the supply voltage • Vsupply = V1 = V2 = V3 = …

×