Question

13. The resistance of platinum wire is 6 ohms at 0°C and 7.2 ohms at
100°C. The temperature coefficient of resistance a is..
....Ji

Answer 1

Answer:

160°C

Explanation:

t=

R

100

−R

0

R

t

−R

0

×100=

3.4−2.4

4−2.4

×100=

1

1.6

×100

=160°C

hope it's helpful to you!

Answer 2

Answer:

The temperature coefficient of the resistance is 0.002$\frac{ohm}{k}$.

Explanation:

Given:

$R_{T_{1} }$ = 6ohm

$R_{T_{2} }$ = 7.2ohm

$T_{1}$ = 0°

$T_{2}$ = 100°

Here,

The temperature at the resistance of value 6ohms is denoted by $T_{1}$.

The temperature at the resistance of value 7.2ohms is denoted by $T_{2}$.

The resistance at temperature $T_{1}$ is denoted by $R_{T_{1} }$.

The resistance at temperature $T_{2}$ is denoted by $R_{T_{2} }$.

Now,

By the equation,

$R_{T_{2} } =R_{T_{1} }(1+\alpha (T_{2}-T_{1})) \\7.2 =6(1+\alpha (100-0))$

$\alpha$ = 0.002 $\ohm$$\frac{ohm}{k}$

So, the temperature coefficient of resistance is equal to 0.002$\frac{ohm}{k}$.