13) If the diameter of a finite length conductor reduces to half, then its resistance

14) Power factor of RC circuit is

15) Resistance of a copper wire is R. Four such wires with the same cross sectional area, but twice the length are connected in parallel, the net resistance is

16) Resistance of a galvanometer is 0.5 Ohm and full scale deflection corresponds to 10 mA. What is the shunt resistor required to increase the range of the instrument to 1 A.

17) Temperature coefficient of resistance of a material is 0.005 Ohm/Degree centigrade. At 20 Degree centigrade, the resistance of a wire made up of this material is 1 Ohm. At what temperature the resistance will become 2 Ohm.