प्रकाश तरंगों का कौनसा गुण उनके अनुप्रस्थ (Transverse) होने का निश्चित प्रमाण देता 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?