Q34 of 37 Page 1

Suggest an idea to convert a full wave bridge rectifier to a half wave rectifier by changing the connecting wire/s. Draw the diagram and explain your answer.

Wave rectifier is used to convert the ac voltage source into dc voltage source. The p-n junction diode and step-down transformer are used to form the rectifier. The full wave bridge rectifier uses four diodes to rectify the ac voltage.

The circuit diagram is shown below:





The circuit can be changed into the half wave rectifier by removing the diodes D2 and D4 because they are responsible for rectifying the voltage when it is in negative cycle. When these two diodes will be removed the positive cycle of ac voltage will be rectified by diodes D1 and D3 as they are in forward bias. The output received will be due to these two diodes only and it will be similar to the half wave rectifier output.


More from this chapter

All 37 →
32

Define resolving power of an astronomical refracting telescope and write expression for it in normal adjustment. Assume that light of wave length 6000Å is coming from a star, what is the limit of resolution of a telescope whose objective has a diameter of 2.54m?

OR


Write the basic assumptions used in the derivation of lens – maker’s formula and hence derive this expression.


 33

Show that can not spontaneously emit a proton.

Given: = 238.05079u, = 237.05121u, = 1.00783u


 35

(a) Using Gauss’s law, derive expression for intensity of electric field at any point near the infinitely long straight uniformly charged wire.

(b)The electric field components in the following figure are Ex = αx, Ey = 0, Ez= 0; in which α = 400 N/C m. Calculate (i) the electric flux through the cube, and (ii) the charge within the cube assume that a = 0.1m.



OR


(a) Define electrostatic potential at a point. Write its SI unit.


Three charges q1, q2 and q3 are kept respectively at points A, B and C as shown in figures. Write the expression for electrostatic potential energy of the system.


(b) Depict the equipotential surfaces due to


(i) an electric dipole


(ii) two identical negative charges separated by a small distance.


 36

In the following diagram, the arm PQ of the rectangular conductor is moved from x= 0; outwards. The uniform magnetic field is perpendicular to the plane and extends from x = 0 to x = b and is zero for x >b. Only the arm PQ possesses substantial resistance ‘r’. Consider the situation when the arm PQ is pulled outwards from x = 0 to x = 2b, and is then moved back to x = 0 with constant speed ‘ѵ’. Obtain expressions for the (i) electric flux, (ii) the induced emf, (iii)the force necessary to pull the arm and (iv) the power dissipated as Joule heat. Sketch the variation of these quantities with distance.


OR


Write working principle of cyclotron and with a suitable diagram explain its working. Give any two applications of cyclotron.