Calculate the value of resistor:
1. What are the significant differences in the way ammeters and voltmeters are connected. If an ammeter reads 2.5 A for a period of 4 minutes, determine the charge that has passed through the ammeter.
2. Calculate the value of resistor x and the current passing through it.
3. An electric heater is connected to a constant 250 V voltage source and absorbs 1000 W. The heater is subsequently connected to a 210 V voltage source. What is the resistance of the heater? What power does the heater absorb from the 210 V source?