  In this work, we have studied simple models that can be solved analytically
to illustrate various fluctuation theorems. These fluctuation theorems provide
symmetries individually to the distributions of physical quantities like the
classical work ($W_c$), thermodynamic work ($W$), total entropy ($\Delta
s_{tot}$) and dissipated heat ($Q$), when the system is driven arbitrarily out
of equilibrium. All these quantities can be defined for individual
trajectories. We have studied the number of trajectories which exhibit
behaviour unexpected at the macroscopic level. As the time of observation
increases, the fraction of such atypical trajectories decreases, as expected at
macroscale. Nature of distributions for the thermodynamic work and the entropy
production in nonlinear models may exhibit peak (most probable value) in the
atypical regime without violating the expected average behaviour. However,
dissipated heat and classical work exhibit peak in the regime of typical
behaviour only.
