Answer:
5. Solenoid B’s magnetic field is 2.7 times greater than solenoid A's magnetic field.
Explanation:
The magnetic field produced by a solenoid depends on number of coils, the length of the solenoid and the amount of current flowing through the coil.
[tex]B=\frac{\mu \times N \times I}{L}[/tex]
Current in solenoid B is 2 times greater than the current in solenoid A.
[tex]I_B=2I_A[/tex]
Number of coils in B is 4 times greater than coils in A
[tex]N_B=4N_A[/tex]
Length of the solenoid B is 3 times greater than solenoid A
[tex]L_B=3L_A[/tex]
[tex]B_B=\frac{2\times 4}{3} B_A=2.7 B_A[/tex]
Thus, solenoid B's magnetic field is 2.7 times greater than magnetic field of solenoid A.