Question 629: Current Electricity

Question

The resistance of platinum wire at $$0^{\circ} \mathrm{C}$$ is $$2 ~\Omega$$ and $$6.8 ~\Omega$$ at $$80^{\circ} \mathrm{C}$$. The temperature coefficient of resistance of the wire is :

Accepted Answer

$$\mathrm{R}_{\mathrm{T}}=\mathrm{R}_{0}\left[1+\alpha\left(\mathrm{T}-\mathrm{T}_{0}ight)ight]$$
$$6.8=2[1+\alpha(80-\alpha)]$$
$$\alpha=\frac{2.4}{80}=0.03 /{ }^{\circ} \mathrm{C}=3 	imes 10^{-2} /{ }^{\circ} \mathrm{C}$$

Answer

$$3 	imes 10^{-3} \mathrm{C}^{-1}$$

Answer

$$3 	imes 10^{-2} \mathrm{C}^{-1}$$

Answer

$$3 	imes 10^{-10} \mathrm{C}^{-1}$$

Answer

$$3 	imes 10^{-4} \mathrm{C}^{-1}$$

Current Electricity

The resistance of platinum wire at $0^{\circ} \mathrm{C} is 2 ~\Omega and 6.8 ~\Omega at 80^{\circ} \mathrm{C}$. The temperature coefficient of resistance of the wire is :

Choose the correct answer: