एक वृत्त की परिधि पर स्थित बिंदु द्वारा अनुरेखित वक्र, जब वह किसी स्थिर वृत्त के अंदर बिना फिसले लुढ़कता है, कहलाता है:

Who among the following founded the 'Forward Bloc'?

Which of the following statements regarding the Harappan Civilization is NOT correct?

Which ruler is generally credited with unifying much of Northern India under a single empire for the first time?