Honey collection improves when beehives are kept in crop fields during flowering periods?Explain.

Why does a beekeeper keep beehives in crop fields during the flowering periods? State any two advantages.

Why are beehives kept in crop field during flowering period? Name any two crop fields where this is practiced.

Explain the process of artifical hybridisation to get improved crop variety in (i) plants bearing bisexual flowers (ii) female parent producing unisexual flowers.

Draw the pattern of electric field lines, when a point charge -Q is kept near an unchanged conducting plates.

Draw a schematic diagram of a cyclotron. Explain the underlying principle and working , stating clearly the function of the electric and magnetic fields applied to the charged particle. Deduce an expression for the period of revolution and show that it does not depend upon the speed of the charged particle.

While studying pollution of water, a group of students observed mortality of fish in the river flowing through the city and also in the pond which was away from the city but was adjacent to the crop fields. They further found that drains of the city discharged sewage into the river and the water from farms flowed into the pond. Explain how these could be the cause of fish mortality.

Define electric potential at a point. When kept in an electric field, does a proton move form lower to higher potential or from higher to lower potential region?

Calculate the force and torque acting on an electric dipole placed in an external unifrom electric field, and define dipole moment and explain when the torque is maximum and minimum.