Magnetic Effect of a Current

8/3/2019 Magnetic Effect of a Current

1/13

Force, Energy &Communication

Lesson 5


2/13

Lesson Objectives

To consolidate our knowledge on electrical

power from last lesson

To look at the costing for electricity

To investigate the magnetic effect of a

current


3/13

REMEMBER!

Charge passed = Current X Time

(coulombs) (amperes) (seconds)

Q = I t

Electrical power = Current X Voltage

(watts) (amps) (volts)

P = I V


4/13

Cost of Electricity

cost of electricity = power (kW) x time (h)

x cost of 1kWh


5/13

Copy and complete this tableAppliance Rating

(kW)

Time (h) Energy

(kWh)

Cost at 10p

per unitStorage heater 2 4 2 x 4 = 8 8 x 10 = 80p

Cooker 7 2

1-bar electricfire

1 1.5

Kettle 2 0.1

Iron 1 1.2

Fridge 0.12 24.0

Lamp 0.06 6.0

CD player 0.012 2.0


6/13

Copy and complete this tableAppliance Rating

(kW)

Time (h) Energy

(kWh)

Cost at 10p

per unitStorage heater 2 4 2 x 4 = 8 8 x 10 = 80p

Cooker 7 2 7x2 = 14 14x10 = 140p

1-bar electricfire

1 1.5 1x1.5 = 1.5 1.5 x 10 = 15p

Kettle 2 0.1 2x0.1 = 0.2 0.2 x 10 = 2p

Iron 1 1.2 1 x 1.2 = 1.2 1.2 x 10 = 12p

Fridge 0.12 24.0 0.12x24 = 2.88 2.88 x 10 = 28p

Lamp 0.06 6.0 0.06x6.0= 0.36 0.36 x 10 = 3.6p

CD player 0.012 2.0 0.012x2= 0.024 0.024 x 10 = 0.24p


7/13

Copy and complete the following summary usingthese words

joules

energy

twice

energy voltage

previous

subtract

To find the number of units used on an

electricity bill, .. the

meter reading from the present one. You

pay for the . you have used not

the .. or the current supplied. If alabel on an appliance says 1kWh it

means it will use .. at the rate of

1000 per second . A 2kW

appliance uses energy .. asquickly as a 1kW appliance.


8/13

Electromagnetic induction
http://bednorzmuller87.phys.cmu.edu/demonstrations/electricityandmagnetism/magneticfields/demo6307.mpg


9/13


10/13

The magnetic force on acurrent When a current flows

through a wire held

between two poles of a

magnet there is anupwards force on it.


11/13

The magnetic force on acurrent The force becomes stronger if

the current is increased

a stronger magnet is used

there is a greater length of wire in the

magnetic field


12/13

The magnetic force on acurrent The force isnt always

upwards .

It depends on the

current and the fielddirections.

If the wire is in line with

the field, there isnt any

force at all.


13/13

Lesson Objectives

To consolidate our knowledge on electrical

power from last lesson

To look at the costing for electricity

To investigate the magnetic effect of a

current

Magnetic Effect of a Current

Documents

Transcript of Magnetic Effect of a Current