The drawing shows three different resistors in two different

The drawing shows three different resistors in two different circuits. The battery has a voltage of V = 10.5 V, and the resistors have resistances of R1 = 50.0 ?, R2 = 25.0 ? and R3 = 10.0 ?. Determine the current through and the voltage across each resistor.

Solution

a)since the resistors are in series :

total resistance=r1+r2+r3=50+25+10=85

voltage=10.5

current=voltage/resistance=10.5/85

currrent flow through all resistors is same since all resistors are in series

i1=i2=i3=0.1235 amperes

v1=i*R1=0.1235*50=6.175volts

v2=i*R2=0.1235*25=3.0875volts

v3=1.235volts

b)the resistors are in series

1/R=1/R1+1/R2+1/R3=1/50+1/25+1/10=8/50

R=50/8

current=voltage /resistance=10.5*8/50=84/50=1.68 amperes

since resistors are in parallel voltage of all resisitors are same

v1=v2=v3=10.5volts

i1=v1/R1=10.5/50=0.21amperes

i2=v2/R2=10.5/25=0.42 amperes

i3=1.05