The most effective measure against injustice adopted by Gandhiji was----------,

Fasting was indeed Gandhi's most effective weapon against injustice, which he called 'satyagraha' or 'soul force'. He used fasting effectively in various contexts - against the separate electorates for Harijans, during communal riots, and as a means of self-purification and moral persuasion. His fasts could mobilize millions and force authorities to address grievances.