While measuring diameter of wire using screw gauge the following readings were noted. Main scale reading is \( 1 \, \text{mm} \) and circular scale reading is equal to \( 42 \) divisions. Pitch of screw gauge is \( 1 \, \text{mm} \) and it has \( 100 \) divisions on circular scale. The diameter of the wire is \( \dfrac{x}{50} \, \text{mm} \). The value of \( x \) is:
