Chapter 28Direct-Current CircuitsMULTIPLE CHOICE1.At what rate is thermal energy being generated in the 2R-resistor when e = 12 V and R = 3.0 W?a.12 Wb.24 Wc.6.0 Wd.3.0 We.1.5 WANS:CPTS:2DIF:Average2.At what rate is thermal energy generated in the 30-W resistor?a.20 Wb.27 Wc.60 Wd.13 We.30 WANS:DPTS:2DIF:Average3.What is the magnitude of the potential difference across the 20-W resistor?a.3.2 Vb.7.8 Vc.11 Vd.5.0 Ve.8.6 VANS:BPTS:2DIF:Average4.What is the current in the 10-W resistor ?a.0.60 Ab.3.0 Ac.1.2 Ad.2.4 Ae.0.30 AANS:APTS:2DIF:Average5.At what rate is thermal energy generated in the 20-W resistor when e = 20 V?a.6.5 Wb.1.6 Wc.15 Wd.26 We.5.7 WANS:BPTS:2DIF:Average6.At what rate is thermal energy generated in the 5-W resistor when e = 24 V?a.13 Wb.3.2 Wc.23 Wd.39 We.51 WANS:BPTS:2DIF:Average7.When a 20-V emf is placed across two resistors in series, a current of 2.0 A is present in each of the resistors. When the same emf is placed across the same two resistors in parallel, the current through the emf is 10 A. What is the magnitude of the greater of the two resistances?a.7.2 Wb.7.6 Wc.6.9 Wd.8.0 We.2.8 WANS:APTS:3DIF:Challenging8.A resistor of unknown resistance and a 15-W resistor are connected across a 20-V emf in such a way that a 2.0 A current is observed in the emf. What is the value of the unknown resistance?a.75 Wb.12 Wc.7.5 Wd.30 We.5.0 WANS:DPTS:2DIF:Average9.What is the current in the 15-W resistor when e = 9.0 V?a.0.20 Ab.0.30 Ac.0.10 Ad.0.26 Ae.0.60 AANS:APTS:2DIF:Average10.How much heat is produced in the 10-W resistor in 5.0 s when e = 18 V?a.72 Jb.32 Jc.50 Jd.18 Je.90 JANS:DPTS:2DIF:Average11.Determine e when I = 0.50 A and R = 12 W.a.12 Vb.24 Vc.30 Vd.15 Ve.6.0 VANS:BPTS:2DIF:Average12.Determine R when I = 0.20 A and e = 18 V.