Question

A 150 ohm electric heater can take a maximum current of 1.1a. What minimum resistance should be joined in series with it that it may be operated at 220v mains

Answer 1

The heater can take a maximum current of 1.1  ampere we need to add a resistance to the circuit in series with the heater is 50 ohm

1. It is calculated by using the Ohm's law
2. V=IR here V is the voltage applied , I is the current and R is the resistance
3. According the question maximum current is 1.1 A
4. Let us assume that R is the resistance to be added  
5. Now 220=1.1(150+R)
6. R = 200-150= 50 ohm

Answer 2

Answer:

150(1+r)=220

please

solve for r