### ANSWER KEY: OHM’S LAW EXERCISE2

Exercise2

1.            Suppose that the dc generator in Figure 1 produces 10 V and the potentiometer is set to a value of 10 ohms. What is the current?                    1 A

2.            Imagine that dc generator in Figure 1 produces 100 V and the potentiometer is set to 10 kiloohms. What is the current?                                10 mA

3.            Suppose that dc generator in Figure 1 is set to provide 88.5 V, and the potentiometer is set to 477 Megaohms. What is the current?         0.186 uA

4.            Suppose the potentiometer in Figure 1 is set to 100 ohms, and the measured current is 10 mA. What is the dc voltage?                1 V

5.            Adjust the potentiometer in Figure 1 to a value of 157 kiloohms, and suppose the current reading is 17.0 mA. What is the voltage of the source?          2.67 KV

6.            Suppose you set the potentiometer in Figure 1 so that the meter reads 1.445 A, and you observe that the potentiometer scale shows 99 ohms. What is the voltage?  143.055 V

7.            If the voltmeter in Figure 1 reads 24 V and the ammeter shows 3.0 A, what is the resistance of the potentiometer?                8 ohms

8.            What is the value of the resistance in Figure 1 if the current is 18 mA and the voltage is 229 mV?          13 ohms

9.            Suppose the ammeter in Figure 1 reads 52 uA and the voltmeter indicates 2.33 kV. What is the resistance?                      45 Megaohms

10.          Suppose that the voltmeter in Figure 1 reads 12 V and the ammeter shows 50 mA. What is the power dissipated by the potentiometer?           0.60 W

11.          If the resistance in the circuit of Figure 1 is 999 ohms and the voltage source delivers 3 V, what is the power dissipated by the potentiometer? 9 mW

12.          Suppose the resistance in Figure 1 is 47 kiloohms and the current is 680 mA. What is the power dissipated by the potentiometer?  22 KW

13.          How much voltage would be necessary to drive 680 mA through a resistance of 47 kiloohms?                32 KV

14.          Consider five resistors in parallel. Call them R1 through R5. Let the resistance values be as follows: R1 = 100 ohms, R2 = 200 ohms, R3 = 300 ohms, R4 = 400 ohms, and R5 = 500 ohms. What is the total resistance? 43.8 ohms

15.          cont....  What is the total conductance?      0.02283 S or Mho