Answer:
(a) Current will be 
(b) Number of ions will be 
Explanation:
We have given that resistance of the biological cell 
(a) We have given potential difference of 75 mV
So 
From ohm's law we know that current is given by

(b) We have given time t = 0.74 sec
We have to find the charge
We know that charge is given by Q = it, here i is current and t is time
So charge will be 
So number of ions will be 
Answer:
The least efficient light bulb is the first one (25 W - 210 Lumen)
Explanation:
Efficiency can be defined as what you want to obtain over what you need to produce it. In this case Eff= Wattage / Lumen. For each light bulb, their efficiency is: 8.4 / 11.12 / 15.7 Lum/W
The answer is (B 60N) hope it helps and have a good day!