A wire has a resistance of 5 Ω at 20°C. If the temperature coefficient of resist
Practice Questions
Q1
A wire has a resistance of 5 Ω at 20°C. If the temperature coefficient of resistivity is 0.004/°C, what will be its resistance at 100°C?
5.4 Ω
6.4 Ω
7.4 Ω
8.4 Ω
Questions & Step-by-Step Solutions
A wire has a resistance of 5 Ω at 20°C. If the temperature coefficient of resistivity is 0.004/°C, what will be its resistance at 100°C?
Step 1: Identify the initial resistance (R0) of the wire, which is 5 Ω.
Step 2: Identify the initial temperature (T0), which is 20°C.
Step 3: Identify the final temperature (T), which is 100°C.
Step 4: Identify the temperature coefficient of resistivity (α), which is 0.004/°C.
Step 5: Use the formula for resistance change with temperature: R = R0(1 + α(T - T0)).
Step 6: Calculate the change in temperature (T - T0): 100°C - 20°C = 80°C.
Step 7: Multiply the temperature coefficient (α) by the change in temperature: 0.004 * 80 = 0.32.
Step 8: Add 1 to the result from Step 7: 1 + 0.32 = 1.32.
Step 9: Multiply the initial resistance (R0) by the result from Step 8: 5 Ω * 1.32 = 6.6 Ω.
Step 10: The final resistance at 100°C is 6.6 Ω.
Temperature Coefficient of Resistance – This concept involves understanding how the resistance of a material changes with temperature, specifically using the formula R = R0(1 + α(T - T0)).
Resistance Calculation – The calculation of resistance based on initial resistance, temperature change, and the temperature coefficient.