Two blocks of masses 10 kg and 20 kg are connected by a massless string and are placed on a smooth horizontal surface as shown in the figure. If a force F = 600 N is applied to 10 kg block, then the tension in the string is

(4)
Here,
Let be tension of the string and be common acceleration of the system.

When a force is applied on 10 kg block, then the tension in the string is