Electricity help, calculating the current

[ella_101]

In a motor vehicle, a relay is used to switch the 12 V , 60 W headlight on and off.


The resistance of the relay coil is 150 ohms . Calculate the current in the relay coil when it is connected to a 12 V supply.

 

[blindside]

On this site it seems people prefer to encourage independent thought rather than just give the solution, but I'm not sure there's much else to say here. The relations relevant at this level are:

$$V = IR$$

$$P = IV$$

 

[Moetasim]

To calculate the current in the relay coil, we can use Ohm's Law which states that current (I) is equal to voltage (V) divided by resistance (R). In this case, we have a voltage of 12 V and a resistance of 150 ohms, so the current can be calculated as follows:

I = V/R
I = 12 V / 150 ohms
I = 0.08 amps

Therefore, the current in the relay coil when it is connected to a 12 V supply is 0.08 amps. This information is important in understanding the power consumption and electrical load of the headlight circuit in a motor vehicle.