Ques.21. Determine the temperature coefficient of resistance of material used in a resistor, if the resistance at 25°C is 50 Ω and 70°C is 57.2 Ω
- 0.007
- 0.005
- 0.003
- 0.008
Ques.22. The resistance of a certain conductor is 18.6 ohms. Find the resistance of another conductor of the same material if its length is the five times the area is three times
- 21.0 Ohms
- 27.0 Ohms
- 29.0 Ohms
- 31.0 Ohms
Ques.23. Which of the following Indian Standards deal with Inductor motors?
- IS: 2026
- IS: 325
- IS:2028
- IS: 3456
Ques.24. The electric strength of the air barometric pressure of 76 cm and 25°C is
- 30 kV/meter
- 21.1 kV r.m.s/cm
- 21.1 kV r.m.s/cm
- 21.1 kV/cm
Ques.25. The critical value of surge impedance of large transmission line is
- 50 ohm
- 500 ohm
- 75 ohm
- 1000 ohm
Ques.26. The surge impedance of telephone line is
- 75 ohm
- 600 ohm
- 500 ohm
- 50 ohm
Ques.27. If A, B, C, D are constants of the medium transimission line, which of the following relation is correct
- AB − CD = −1
- AB + BD = 1
- BC − AD = −1
- AC − BD = 1
Ques.28. What is the unit of resistivity?
- Ohm-m
- Mho-m
- Henry
- None of these
Ques.29. The surge impedance of an Underground cable is
- 60 to 100 ohm
- 40 to 600 ohms
- 40 to 60 ohms
- 30 to 75 ohms
Ques.30. As the transmission voltage increase the volume of the conductor is
- Increase
- Decrease
- Will not change
- Will increase in random Manner