Question

plz give me the answer of these questions ​

Answer 1

Explanation:

For greater accuracy of potentiometer,the potential gradient of slope(V/I) should be small as possible. So,slope(V/I) is smaller for Y.So we should prefer Y

w.k.t

I=V/R=5/20=1/4 A

Resistance of 60cm wire=15/100×60=9 ohm

voltage drop on 60cm wire is V=IR=1/4×9=2.25 V

By kirchoff's law,

27-24-6(I2)-2(I1)=0

6(I2)+2(I1)= 3------(1)

27-4(I3)+6(I2)=0

4(I3)-6(I2)=27-----(2)

from figure,I1=I2+I3

from (1),

6(I2)+2(I2+I3)= 3

8(I2)+2(I3)= 3-----(3)

from(2) and (3)

20(I2)=30

I2=3/2 A=1.5A

Substitute in (3)

12+2(I3)=3

2(I3)= -9

I3= -9/2 A= -4.5 A

I1=3/2 -9/2= -3A