A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are mutually perpendicular and bisect each other. The time period of the combination is $4 \mathrm{s}$. If one of the magnets is removed, then the time period of other one will be

• A

  $\text{5.78} \mathrm{s}$
• Correct answer
  B

  $\text{3.36} \mathrm{s}$
• C

  $\text{4.36} \mathrm{s}$
• D

  $\text{5.36} \mathrm{s}$

Hence, the correct answer is option: 'B'.