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What is the voltage across R1? _________
What is the voltage across R2? _________ 
What is the voltage across R1? _________ What is the voltage across R2? _________ What is the voltage acrossR3? _________ 
What is the voltage across R1? _________ What is the voltage across R2? _________ 
The voltage across R2 is 8 volts. What is the battery voltage? _________ 
The current flowing through R1 is 800 mA. What is the current flowing through R2? ________ 
How much current is flowing through R1? _________ 
Question 1: The
resistors are equal, therefore the voltages across them is equal. These
two voltages must add up to the battery voltage (10 volts). Therefore,
each resistor has 5 volts across it.
Question 2: Same as question 1. The resistors are equal, therefore the voltages are equal, they must add up to 15 volts. Each resistor has 5 volts across it. Question 3: R2 has twice the value of R1 so it must have twice the voltage across it. The voltages must add up to 15 volts. Therefore R1 has 5 volts and R2 has 10 volts. Question 4: R2 has twice the value of R1, it must have twice the voltage. Therefore R1 has 4 volts across it. The battery voltage must be the sum of the resistor voltages, which are 8 volts and 4 volts. Therefore the battery voltage is 12 volts. Question 5: This is a series circuit. The current is the same everywhere. Therefore the current through R2 is 800 mA. Question 6: Don't make the mistake of dividing 20 volts by 5 ohms. R1 has only a fraction of the battery voltage across it. R1 has 1/4 of the total resistance so it has 1/4 of the total voltage. 1/4 of 20 volts is 5 volts. 5 volts divided by 5 ohms = 1 ampere. 
What is the value of the top resistor?

Total resistance is 75 ohms

The ground symbol represents 0 volts. At the top of the 100k resistor there are 10 volts. What is the voltage at the top of the 200k resistor? 
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