Answer:
Aluminium
Explanation:
When a body is immersed in a liquid partly or wholly it experiences an upward force which is called buoyant force.
The amount of buoyant force depends on the volume of body immersed, density of liquid and the value of acceleration due to gravity.
Here, the density of liquid is same in both the cases and g be the same. So, here the amount of buoyant force depends on the volume of body immersed.
As the density of lead is more than the density of aluminium, so the volume of aluminium is more than lead, as volume is equal to mass divided by density. So, the buoyant force acting on the aluminium is more than lead.
To solve this problem we will apply the concepts related to Ohm's law and Electric Power. By Ohm's law we know that resistance is equivalent to,

Here,
V = Voltage
I = Current
While the power is equivalent to the product between the current and the voltage, thus solving for the current we have,


Applying Ohm's law


Therefore the equivalent resistance of the light string is 
Answer:19ohms
Explanation:
equivalent resistance=5+2+12
equivalent resistance=19ohms
Gravity is the correct answer.