The vernier scale used for measurement has a positive zero error of 0.2 mm. If while taking a measurement it was noted that 0 on the vernier scale lies between 8.5 cm and 8.6 cm. Vernier coincidence is 6, then the correct value of measurement is cm. (least count = 0.01 cm)

The vernier reading is computed as: main scale reading + (vernier coincidence $$\times$$ least count) $$-$$ zero error. The main scale reading (MSR) is 8.5 cm since the zero of the vernier lies between 8.5 cm and 8.6 cm. The vernier coincidence is 6 and the least count is 0.01 cm.

The observed reading is $$8.5 + 6 \times 0.01 = 8.5 + 0.06 = 8.56$$ cm. Since the instrument has a positive zero error of 0.2 mm = 0.02 cm, the corrected reading is $$8.56 - 0.02 = 8.54$$ cm.

The correct answer is option 2: 8.54 cm.