Influence of magnitude and direction of static magnetic field applied on adrying drop of a laboratory synthesized water base ferrofluid placed on a planeglass plate is investigated. Like all other multi-component fluid this dropalso exhibited familiar coffee ring pattern in absence of field while, thispattern is modulated by applying magnetic field and thickness of the ringmodulated by the applied field and thickness of the ring decreasesexponentially with increase in field when direction of field is normal to theplane of the substrate. Effect of the field on the evaporation rate andtemporal variation of contact angle is also studied. Results are analysed inlight of available models. The findings may be useful in applications likeink-jet printing, painting and display devices involving ferrofluids.
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