निम्नलिखित में से किस समस्थानिक (isotope) का उपयोग आमतौर पर परमाणु ऊर्जा संयंत्रों में ईंधन के रूप में नहीं किया जाता 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?