Final answer:
To determine the resistance of a silicide block, it is important to know if the material is ohmic or non-ohmic. For non-ohmic materials, the resistance is not constant and depends on the voltage and temperature, requiring specific measurements and calculations.
Step-by-step explanation:
To find the resistance of a silicide block, we need to consider whether the material is ohmic or non-ohmic. An ohmic material has a resistance that remains constant regardless of the applied voltage, and can be determined from the slope of the voltage-current graph. However, the student's question implies that the material in question may be non-ohmic, as indicated by the resistance not remaining constant. In case the material is non-ohmic, such as a silicide with a non-linear voltage-current relationship, more complex methods must be used to determine the resistance, such as measuring the current through the resistor under different voltages.
If a non-ohmic relationship is specified, like the current being inversely proportional to the square of the voltage, then this functional relationship can be used to calculate resistance under specific conditions. For a wire made of the same material with double the diameter but the same length, the resistance will be different, and can be calculated using the resistivity formula R = ρL/A, where ρ is the resistivity, L is the length, and A is the cross-sectional area.
To calculate resistance changes at different temperatures, the formula R = R0(1 + αΔT) can be used, where R0 is the original resistance, α is the temperature coefficient of resistance, and ΔT is the change in temperature. Lastly, resistance in a series of elements, such as ceramic insulators, can be added to determine the total resistance.