1) a 12m length of wire with uniform cross sectional area 2.75x10^-7 has a potential difference of 15v applied across it, producing a current of 20A
a) find the resistivity of the wire B) what is the power dissipated in the wire?
2) 2 circuits are made. In circuit 1, 4 resistors (1,2,3,6 ohms) are connected in series. in circuit 2, the same 4 resistors are connected in parallel. The battery emf is 24 volts in both cases. Calculate the equivalent resistance of the each circuit and the current through each resistor.
determine the equivalent resistance and the total power deliverd by the battery for this ciruit.
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The Attempt at a Solution
1) a) r=I/V r=15/20 r=.75
b) p=IV p=20*15 p=300
2) Equivalent resistance for the series would be 12 because i just added the resistors up and i solved for current doing 24=I(12) V=IR so then the current through each resistor would be 2,4,6,12 respectively
for the parallel i did 1/rp=1/r1+1/r2+1/r3+1/r4 and got 1/3=rp, i solved current using v*r=I
24(1/3)=8 and then for each resistor the current was 24,12,8,4 respectively.
3) I am totally confused on this one?