Transcript Circuit Construction Power Point

1
Simple circuit
Simple circuit
Connect the solar cell to a resistance.
▫ Measure the resistance and current.
▫ Repeat for different resistors.
▫ Can you find the relationship between
voltage, current and resistance?
2
Ohm’s Law and Current
Measurement
Connect 1.5V battery to the two resistors connected in series.
a) Measure the voltage across each resistor.
b) Calculate the current in the circuit using Ohm’s law and
verify experimentally
Connect 1.5V battery to the two resistors connected in parallel.
a) Measure the voltage across each resistor.
b) Calculate the current in the circuit, through each resistor
using Ohm’s law and verify experimentally.
3
Home assignment
Take a look at your KUB bill. What are we
charged for? power or energy used?
What do you think is the unit cost of
electricity we pay?
How are appliances rated- power or
energy? Please list the rating of atleast two
electric appliances.
4
Short Circuit and Open circuit
In an open circuit, no current flows.
A short circuit exists whenever the
resistance of a circuit or the resistance of a
part of a circuit drops in value to almost
zero ohms.( R~=0) This causes an infinite
(huge) current!!!
Closed circuit is one where there is a finite
amount of current flow.
5
Appliance
Watts
Computer
20-75
Desktop PC
80-200
Bulbs (incandescent)
40-100
Compact Fluoroscent Lamps(CFL)
11-23
Microwave
600-1500
Refrigerator( 20cf)
540
Air conditioner( central/ room)
2000-5000 /1000
Fan(ceiling)
10-50
Dishwasher
1500
Washing machine/dryer
500/ 4000
toaster
800-1500