Answer : The amount of current used to warm your feet is, 0.1 A
Explanation :
To calculate the current we are using ohm's law:
![V=IR](https://img.qammunity.org/2021/formulas/physics/high-school/8gv7kiyicaqmg4zdl8vw77xnncjzk66hn7.png)
where,
V = voltage = 9 V
I = current = ?
R = resistance = 90 Ω
Now put all the given values in the above formula, we get the current.
![V=IR](https://img.qammunity.org/2021/formulas/physics/high-school/8gv7kiyicaqmg4zdl8vw77xnncjzk66hn7.png)
![9V=I* 90\Omega](https://img.qammunity.org/2021/formulas/physics/middle-school/sgo4n2jy2seot51iph4zankssyp5bberz1.png)
![I=0.1A](https://img.qammunity.org/2021/formulas/physics/middle-school/tnyc34a9zb5z17rihnhkerax2fnwpjfzot.png)
Therefore, the amount of current used to warm your feet is, 0.1 A