Question

please solve the question given in the attachment.

Answer 1

heya dear your answer is here
______________

V=IR

12=I*6

I= 2A

here both resistance are in series so current Flowing from both are same

so ammeter reading is 2A

and

V=IR

6=2*R

R=3 Ohm

potential difference across battery=V1+V2
=6+12 =18V

Answer 2

we see that the two resistances are kept in series
so current through each resistor remains the same
I=V/R
thus for the two resistor we get two equations
I=6/R
and also
I=12/6
this implies 6/R=12/6
=>6/R=2=>2R=6=>R=6/2=3
so the value of R is 3 ohm

reading of ammeter =V/R=12/6=6/3=2A

the equivalent resistance is 3+6=9 ohm
as they are in series
we had got that current is 2A
so Pd by the battery
V=IR=2*9=18 V
hope it is not wrong and helps you