Electrical machine design MCQs
1. Which order of materials is correct according to decreasing value of permeability? (A) Pure iron, silicon iron, aluminum, bismuth (B) Silver, copper, aluminum, Iron (C) Perm alloy, Nickel, air, water (D) Cobalt, Nickel, aluminum, iron 2. The material preferred for pole shoes of electron magnets in electric machines is: (A) Lead (B) Copper (C) Aluminum (D) Pure iron 3. In transformer stamping, the percentage of silicon is usually limited to: (A) 1 % (B) 2 % (C) 3 % (D) 4 % 4. Where annealed copper is used: (A) In machine winding (B) In low voltage cables (C) In flexible wires (D) All 5. For overhead conductors, which variety of copper is used? (A) Annealed copper (B) Native copper (C) Hard drawn copper (D) Purest form of copper 6. Which is odd one out? (A) Dielectric strength (B) Refractive index (C) Emissivity (D) Absorptivity 7. When a material has permeability of 0.999991, it can be classified as: (A) Ferrite (B) Ferro-magnetic material (C) Paramagnetic material (D) Diamagnetic