What should be done to prevent the bunds on a farm from getting washed away in the rainy reason?

Condensers of capacities 5 F and 10 F are connected in parallel in a circuit with a cell of e.m.f. 2V. What should be the capacity of the condenser to be connected in series with parallel combination of the condensers to get 1 C charge to flow in the circuit ?

Answer the following questions: What is done so to prevent rusting of iron windows and iron doors of your house?

The radius of a cone is reduced to half . What should be done to its slant height so that curved surface area remains unchanged .

What should be the velocity of sound from a source w.r.t. an observer, so that the frequency listened by the observer becomes half of the initial frequency?

A girl stands 171 m away from a high wall and claps her hands at a steady rate so each clap coincides with echo of the one before. (I) If she claps 60 claps in 1 min what value should be the speed of sound in air ? (II) Now, she moves to another location and finds that she should now make 40 claps in 1min. to coincides with successive echoes. Calculate the distance for the new position from the wall.

Two charge 5 mu C and - 4 mu C are kept 5.0 m apart at points A and B respectively. How much work will have to be done to move the charge at A through a distance of 5.0 m further away from point B along the line BA

Answer the following in one or two sentences What is done so to prevent rusting of iron windows and iron doors of you houseA?

What is wavefront ? What is the shape of the wavefront at a point far away from the source of light?