Step-by-step explanation:
The power of an electrical appliance is given by :

Where
V is the voltage source
I is the current flowing in the circuit
1. For 1200 W microwave, Current, I = 10.9 A
2. For 1500 W water heater, Current, I = 6.8 A
3. For 100 W light bulb, Current, I = 0.9 A
4. For 2000 W oven, Current, I = 9.1 A
5. For 40 W light bulb, Current, I = 3.3 A
Out of the above five appliances, the largest current is flowing in microwave and the smallest current is flowing in the light bulb.
So, the sequence from smallest current to the largest current is :
100 W light bulb ( 0.9 A) < 40 W light bulb (3.3 A) < 1500 W water heater (6.8 A) < 2000 W oven (9.1 A) < 1200 W microwave (10.9 A)