A system is shown in the figure. The time period for small oscillations of the two blocks will be
2π3mk
2π3m2k
2π3m4k
2π3m8k
Both the spring are in series
∴ Keq = K(2K)K+2K = 2K3
Time period
T =2πμKeq where μ = m1m2m1+m2
Here μ = m2
∴ T =2πm2.32K = 2π3m4K