पानी में आंशिक रूप से डूबी हुई सीधी छड़ी सतह पर टेढ़ी दिखाई देती है। इसका कारण क्या है?

The 'Drain of Wealth' theory was propounded by which Indian nationalist leader?

Which event is considered the turning point in Mahatma Gandhi's leadership in the Indian independence movement?

Which African leader is known for his non-violent opposition to colonial rule?