1. In the figure, the current element idl, the point P, and the three vectors (1, 2, 3) are all in the plane of the page.At point P the direction of the vector dB, due to this current element, is: A) in the direction marked "3" B) in the direction marked "1" C) out of the page D) into the page E) in the direction marked "2" 2. A 45-mH inductor is connected to an ac source of emf with a frequency of 400 Hz and a rms voltage of 20 V. The RMS current is: 3. In an ideal 1:8 step-downtransformer, the primary power is 10 kW and the secondary current is 25 A. The primary voltage is therefore: Page 1
has intentionally blurred sections.
Sign up to view the full version.
4. Four long straight wires carry equal currents into the page as shown. The direction of the magnetic FORCE exerted on wire F is: A) east B) west C) north D) zero E) south 5. A hollow cylindrical conductor (inner radius = a, outer radius = b) carries a current iuniformly spread over its cross-section (shaded). Which graph below correctly gives the magnitude of Bas a function of the distance rfrom the center of the cylinder? b a Page 2