In a single slit Fraunhofer diffraction pattern obtained at normal incidence, at the angular position of the second diffraction minimum, what is the phase difference (in radians) between the waves from the opposite edges of the slit?

Which of the following territories was annexed by Lord Dalhousie under the pretext of misgovernance, and not directly through the Doctrine of Lapse?

What was the primary stated reason for the Partition of Bengal in 1905 by Lord Curzon?

Which of the following events is considered the immediate trigger for the launch of the Non-Cooperation Movement by Mahatma Gandhi?