Heat shrinkable joint is such a type of cable joint made of glass fiber or cast iron housing where thermally shrinkable PVC tubes or polyethylene (PE) tubes are used as a sleeve to insulate cable joints, shield open conductors and also to seal connectors. Heat shrinkable tubes serve as cable coverings slipped over bare conductors. The internal diameter of these tubes is so chosen that after free shrinkage at 130°C to 180°C temperature on exposure to the stream of hot air, or the flame of a burner rapidly moved along the tube the internal diameter of the tube becomes 10% to 20% smaller than the external diameter of the cable conductor to be insulated. So this tube on heating tightly envelops the joint leaving no free space inside. The length of the tubes should be selected considering 10% to 15% linear shrinkage. This type of joint is mainly used in high voltage PILC cables.
 Multiple Choice Question (MCQ) of Electronics page-17:241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. c) The saturation voltage VCE for silicon transistor is same as that for germanium. d) The saturation voltage VCE for silicon transistor is lower than germanium transistor. |
Multiple Choice Question (MCQ) of Electronics page-16:226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor. b) Bound electrons are always present in the semiconductor. c) Free electrons are always present in the semiconductor. d) Inner and bound electrons are always present in the semiconductor. |
Multiple Choice Question (MCQ) of Electronics page-15:211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors b) Conductors c) Insulators d) Alloys |
Multiple Choice Question (MCQ) of Electronics page-14:196. In which of the following device the base resistors are not added in the package but added externally? a) UJT b) CUJT c) PUT d) None of the above |
Multiple Choice Question (MCQ) of Electronics page-13:181. The conduction in JEFT is always by the a) Majority carriers b) Minority carriers c) Holes d) Electrons e) Holes and electrons simultaneously |