# Finding resistance/Power Consumption

• glasgowm
In summary, an electric cooker has two settings, high and low, with a voltage of 230V. The resistance for R1 and R2 is 76.6667Ω at the high setting and 230Ω at the low setting. The power consumption for both settings is 230W at the low setting and 690W at the high setting.

#### glasgowm

An electric cooker has two settings, high and low. It takes 1A at the low setting and 3A at the high setting (It lists 230 as the voltage on the diagram)

Find the resistance of R1 & R2 (they are parallel circuits)

V=IR (R= V/I)
high setting: R=V/I ... R = 230V/3A = 76.6667Ω
low setting: R=V/I ... R = 230V/1A = 230Ω

I figure I'm doing something wrong since the answers I come out with a bit weird

Part 2

Calculate the power consumption

P = I²R

P = 1²A*230 | P = 3²A*76.6

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glasgowm said:
high setting: R=V/I ... R = 230V/3A = 76.6667Ω
low setting: R=V/I ... R = 230V/1A = 230Ω

I figure I'm doing something wrong since the answers I come out with a bit weird
Looks good to me.

Part 2

Calculate the power consumption

P = I²R

P = 1²A*230 | P = 3²A*76.6
Also good. But complete the calculation and assign proper units.

(Power consumption can also be calculated using P = VI.)

P = 230W | P = 690W

Your calculations for the resistance of R1 and R2 are correct. The reason the values seem a bit strange is because they are very small resistances, which is common for household appliances. Resistance is measured in ohms (Ω) which is a unit of electrical resistance. In this case, R1 has a resistance of 76.6667Ω and R2 has a resistance of 230Ω.

For the power consumption, your calculations are also correct. The power consumed by the electric cooker is directly proportional to the resistance and the square of the current flowing through it. This is why the power consumption at the high setting is three times greater than at the low setting. This information is important for understanding the energy usage and efficiency of the electric cooker.

## 1. What is resistance?

Resistance is the measure of how much an object or substance impedes the flow of electric current. It is measured in ohms and is represented by the symbol "R".

## 2. How do you calculate resistance?

Resistance can be calculated using Ohm's law, which states that resistance is equal to the voltage divided by the current. The formula is R = V/I, where R is resistance in ohms, V is voltage in volts, and I is current in amperes.

## 3. What factors affect resistance?

The factors that affect resistance include the material of the object, the length and cross-sectional area of the object, and the temperature. Different materials have different resistivity, which determines their resistance. Longer objects and objects with smaller cross-sectional areas have higher resistance. And as temperature increases, resistance also increases.

## 4. What is power consumption?

Power consumption is the amount of electrical energy used by a device or system. It is measured in watts and is represented by the symbol "P".

## 5. How do you calculate power consumption?

Power consumption can be calculated using the formula P = VI, where P is power in watts, V is voltage in volts, and I is current in amperes. It can also be calculated using the formula P = I^2R, where R is resistance in ohms and I is current in amperes.