In a series circuit, there are two consumers. If you add one more battery, what is the change of current? The consumer with high resistance adds more voltage than the consumer with low resistance What is the voltage applied by the appliance?

In a series circuit, there are two consumers. If you add one more battery, what is the change of current? The consumer with high resistance adds more voltage than the consumer with low resistance What is the voltage applied by the appliance?

This depends on whether the new battery is in the same direction as the positive and negative poles of the original power supply. If it is consistent, the current will increase; if it is inconsistent, the current will decrease; the voltage at both ends of the appliance with large resistance is greater than that at both ends of the appliance with small resistance

The voltmeter measures the voltage of the sliding rheostat. When the slide of the sliding rheostat is moved to increase the resistance of the circuit, how does the voltage indication change?
When the resistance increases, the current through the sliding rheostat also decreases. How to judge the change of voltage according to Ohm's law formula?

Assuming that the voltage U and internal resistance R of the power supply are constant, you are talking about the case that the rheostat R1 is connected in series with another constant resistance R2. Then, the larger the resistance R1 of the rheostat, the larger the voltage U1 it gets. If calculated, the current I = u / (R + R1 + R2), the voltage U1 = IR1 = ur1 / (R + R1 + R2)

Are sliding rheostat, constant resistance, ammeter and voltmeter electrical appliances?

It belongs to electrical appliances