###### Module 3 - Electricity Basics

 1. Electrical current is the rate of flow of A electrons B protons C charge D volts

 2. Current = A charge / time B potential difference / time C potential difference x Resistance D charge x time

 3. Potential difference = A work done / time B work done / charge C work done / volt D work done / resistance

4.  A charge of 1.0 coulomb flows for 2 minutes, what is the current? Ampere

5.  A current of 100mA is flowing for 10 minutes, what is the charge passedCoulombs

6.  A current of 10mA passes a charge of 100 Coulombs.  How long is the supply switched on for? seconds

 7. Resistance  = A Potential difference x current B current / potential difference C Potential difference / current D work done / current

8.  Consider this circuit

For the resistor network shown, calculate
a)      the total resistance of the combination    ohms

b)      the p.d. across each resistor:

4ohm: V,  10 ohm: V,  20 ohm: V

c)      the current through each resistor.

4ohm: A,  10 ohm: A,  20 ohm: A

 9. For the circuit shown, calculate     a)    the total resistance of the circuit ohms   b)      I  A   c)      I1 A   d)      I2 A   e)      V1 V   f)      V2 V 10 For the circuit shown, calculate; a)         the total resistance  kilo-ohms b)         the total current (I)  A c)         the branch currents (I1 and I2­) A and A d)         the p.d. across resistor B  V e)         the p.d. across resistor D.  V

 11. Energy   = A Potential difference x current x time B Potential difference x time / current C Potential difference / current D Potential difference x current

 12. Power   = A Potential difference x current x time B Potential difference x time / current C Potential difference / current D Potential difference x current

 13. Power   = A resistance x  current squared B Potential difference x time squared C Potential difference / resistance squared D current x resistance squared

 14 In the circuit shown, a d.c. supply of p.d. V and negligible internal resistance is connected to 400 W and 1600 W resistors arranged in series.  A voltmeter of resistance 2000 W connected across the 400 W resistor gives a reading of 8.0 V. Calculate:     a)  the magnitude of the supply,   V        b) and hence the p.d. across the 1600 W resistor        V       c) the p.d. across the 1600 W resistor when the voltmeter is disconnected.      V