Answer:
d)Cells 1 and 2
Explanation:
In a voltaic cell, oxidation occurs at the anode and reduction occurs at the cathode. The half cell that function as anode or cathode in a voltaic cell depends strictly on the reduction potential of the metal ion/metal system in that half cell.
Examining the reduction potentials of the various metal ion/metal systems in the three half cells;
Cu= +0.34 V
Ni= -0.25 V
Zn= -0.76 V
Fe(Fe2+)= -0.44 V
Hence only Zn2+ has a more negative reduction potential than Fe2+. The more negative the reduction potential, the greater the tendency of the system to function as the anode. Thus iron half cell will function as anode in cells 1&2 as explained in the argument above.
Answer:
22Ω
Explanation:
Given parameters:
Potential difference = 3.3V
Current = 0.15A
Unknown:
Resistance = ?
Solution:
According to ohm's law, potential difference, current and resistance are related by the expression below;
V = I R
where V is the voltage
I is the current
R is the resistance
3.3 = 0.15 x R
R = 
= 22Ω
Answer:
Heat is transferred from the warmer block to the cooler block
Explanation:
Heat transfer by conduction involves two or more solids. The heat generally moves from a part at higher temperature to one with a lower temperature.
- Heat transfer is based on the differences in temperature profile on a body.
- When the temperature of the body is the same, heat is not transferred.
- The molecules that makes up the hotter body collides with static molecules of the cold one.
- Through this, heat is transferred.
