Look at the circuit shown in the figure above. with switch s1 closed and the resistance value of r1 and r2 equal, meter m1 has a current reading of 0.04 A. what will be the current readings on meter M2 and meter M3? A. Meter M2 will read 0.02 A, and meter M3 will read 0.02 A.
B. Meter M2 and meter M3 will both read 0.1 A.
C. Meter M2 and meter M3 will both read 0.04 A.
D. Meter M2 will read 0.2 A, and meter M3 will read 0.4 A.

A. Meter M2 will read 0.02 A, and meter M3 will read 0.02 A

Explanation:

I = Current through M1,

I1 = Current through M2

I2 = Current through M3

According to current division rule,

I1  = { R1 / ( R1 + R2) } * I   ( 1 )

And similarly

I2  = { R2 / ( R1 + R2) } * I ( 2 )

and hence when the Switch S1 is closed and given that the Resistance Value of R1 and R2 becomes equal then the Equation ( 1 ) and equation ( 2 )

becomes :

==>          I1  = { R1 / ( R1 + R1) } * I

==>          I1  = { R1 / 2( R1 ) } * I

==>          I1 = (0.5) * I

and as the value of I is given as 0.04A

therefore:

the value of I1 is 0.04  / 2 = 0.02 A ,

and similarly the value of I2 is also 0.02 A.

so much for the extra points :