Simple circuitSimple circuitConnect 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?

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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.

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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.

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Short Circuit and Open circuitIn 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.

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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

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