Please answer me !!!!!!!!!!!?

Question

Out of two, a heater of 2kW and a toaster of 1kW, which has greater resistance?

There are two formulae of power :-
First is P=I*I*R (According to which P is directy proportional to R)
Second is P=V*V/R (According to which P is inversely proportional to R)

This question was asked in my physics exam today. I am in doubt. Please help...........

Answer 1

Toaster will have high resistance as the voltage is same.

Answer 2

First of all there are two formula for power relating to the motion of electrons;
Electron Power and electric current power.
The electron poweis the Ampere
The electric current power is the Watt.
For P to be inversely proportional to R you have to maintain the emf constant.

So for the same emf 1/2 the resistance you would use twice the power so the 1 kw has the greater resistance.

Answer 3

first of all...they both will not have the same voltage
u have to use current principle
P=i^2 * R
Which ever has the greater resistance can only b caluclated and cant b predicted using the information
depends on each appliance current consumption that must be given

Since this is a Examination problem , may b it must b given that they both have an equal voltage(as earlier answers have assumed)..may be if they both r used on a series connection...than toaster will have a greater resistance

Answer 4

First, the power formula given to you was wrong. P=I*E. Second, power is energy dissipated as heat, measured in watts. If an appliance or other electrical device uses X number of watts, and the voltage of each device is the same, then the higher the watts, the higher the resistance. Therefore, the 2Kw heater would have the higher resistance.

Answer 5

...assuming you're using the same voltage on both the heater and toaster P=V^2/R, R=V^2/P so the 10000/1000 =10 Ohms. 10000/2000 = 5 Ohms. ...so the heater would have lower resistance.

..and omega squared is a dumbass. Think about a short circuit. Very little resistance, lots of heat, lots of current.

Answer 6

The toaster has a higher resistance, IF both units are meant to work on the same voltage.

V and I are related with the equation:

V = I R

that is why the formula

P = V * V /R
can be turned into

P = V I R / R

or P = V I for short.

By the way, just entitling your question "help me !!!!" is not really helping.

Answer 7

If the voltages are the same then the toaster has more resistence. It's drawing less current.

You can't argue with a guy using Ω² as a nickname.

Answer 8

You say,
"First is P=I*I*R (According to which P is directy proportional to R)"

Wrong U must say,
"First is P=I*I*R (According to which P is directy proportional to R ,WHEN I IS CONSTANT)"

samely second statment must be correected like followes,
"Second is P=V*V/R (According to which P is inversely proportional to R, WHEN V IS CONSTANT )"

normaly in domestic supply voltage is constant accross the equipment (230V or 110V) . but current flow through the equipment changes. therefore first statment is not applicable here.

so we have to say in ths cercumstance,
"P is inversely proportional to R, BECAUSE V IS CONSTANT )"

so 1KW has heigher resistance

Answer 9

in household power supply voltage remains constant so 2nd formula is to be used .hence p is inversely proportional to resistance.

Answer 10

use V*V/R

V will be constant in both case. I may vary.

so toaster will higher resistance