Question

Solve q 6 and 7 for 15 points hurry upp
It's urgent

Answer 1

wai please i figure it out right now.
since 8ohm and 12 ohm are in parallel
so they will give equivalent to =12*8/(12+8)=96/20=4.8
that comes to the series of 7.2
so net eqv. resistance =7.2+4.8=12ohms
i=v/r=6/12=.5amps
p.d. across r1=i*r1=.5*7.2=3.6volt

now 7 question
when resistor is streched to double length
its volume remains constant.

so
l1*a1=l2*a2
l*a1=2l*a2
a1=2a2
so r1/r2=l1*a2/(l2*a1)
r1/r2=l*a2/(2l*2a2)
=1/4
r2=4*r1
=4*2=8 ohms

i hope you got the solution.