Exercise3. Complete the sentences writing in the correct modal verbs.

1.For accurate results, the simple Eq. (4.2) _______cannot____ be applied to metallic circuits having finite cross section. In some cases, the finite conductor ______can________ be considered as being divided into a large number of filaments connected in parallel, each having its own induced voltage and its own resistance. In other cases, such as the common ones of D.C. generators and motors and homopolar generators, where there are sliding and moving contacts between conductors of finite cross section, the induced voltage between neighboring points ___________is to________ be calculated for various parts of the conductors. These ___________can___________ then be summed up or integrated. For methods of computing the induced voltage between two points, see text on electromagnetic theory. (cannot; is to; can; can)

2.The field map consists of lines of force and equipo-tential lines which _______can_______ intersect at right angles. In sketching the field map, first draw those lines which ______must_______be drawn by symmetry. (can; must)

The natural frequency (resonance) of mechanical vibration of the conductors ______may_________ add still further to the maximum force, so a factor of safety _____should_________ be used in connection with Eq. (4.16) for calculating stresses on bus bars. (may; should)

Exercise 4. Complete the sentences with the correct infinitive tense.

1.He has grown taller. – He seems to have grown taller.

2.He is getting used to his new job. – He appears to be getting used to his new job.

3.Kate makes friends easily. – Kate tends to make friends easily.

4.He has finished the report. – He claims to have finished the report.

5.They have sailed round the world. – They are reported to have sailed round the world.

Exercise 5. Put the verbs in brackets into the correct infinitive form or gerund form.

1. A capacitor is a circuit element that is described through its principal function, which is to store (store) electric energy.

2. At times it is useful ______to evaluate ________ (evaluate) materials and media by ______ comparing___________ (compare) their energy storage capability on a unit volume basis. 3. In contemporary vector calculus notation, four equations can be written ______to describe __________ (describe) the basic theory of electromagnetic fields. 4. This means that it is possible _____to neglect _________ (neglect) the spatial variations in electromagnetic quantities. 5. Another way of _____saying__________ (say) this is that the dimensions of the circuit are small compared with the wavelengths of the electromagnetic quantities and thus that it is necessary _______to consider ____________ (consider) only time variations. 6. The second fundamental principle, abbreviated KVL, follows from _____applying__________ (apply) the assumption of small size to Faraday's law in integral form. 7. In circuit analysis, the goal is ____to start________(start) with a connected set of circuit elements such as resistors, capacitors, operational amplifiers, and other devices, and ____to find________ (find) the voltages across and currents through each element, additional quantities, such as power dissipated, are often computed. 8. ____To energize____________ (energize) the circuit, sources of electric energy must be connected.