$2 \times 10^{-12}$
Step 1: 1 $\mu$m = $10^6$ pm.
Step 2: Given length is 6 $\mu$m. So, \[ x = 6 \times 10^6 { pm} \] Step 3: Therefore, the correct answer is (D).
Match the LIST-I with LIST-II: 
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Match the LIST-I with LIST-II 
Choose the correct answer from the options given below:
A temperature difference can generate e.m.f. in some materials. Let $ S $ be the e.m.f. produced per unit temperature difference between the ends of a wire, $ \sigma $ the electrical conductivity and $ \kappa $ the thermal conductivity of the material of the wire. Taking $ M, L, T, I $ and $ K $ as dimensions of mass, length, time, current and temperature, respectively, the dimensional formula of the quantity $ Z = \frac{S^2 \sigma}{\kappa} $ is: