Exam 28: Direct-Current Circuits

A resistor of unknown resistance and a 15-Ω 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 certain brand of hot dog cooker applies a potential difference (120 V)to opposite ends of the hot dog and cooks by means of the joule heat produced.If 60 kJ is needed to cook each hot dog,what current is needed to cook four hot dogs simultaneously in 3.0 min?

Determine the potential difference,V_A − V_B,in the circuit segment shown below when I = 2.0 mA and Q = 50 μC.

A parallel circuit consists of a 100 V DC power source,a 100 Ω resistor,and a variable resistor of resistance R,which varies from 0 to 100 Ω.The current in the circuit is

What is the equivalent resistance between points A and B in the figure when R = 18 Ω?

The algebraic sum of the changes of potential around any closed circuit loop is

At what rate is thermal energy generated in the 5-Ω resistor when ε = 24 V?

A circuit consists of 2N resistors,all of resistance R,connected as shown below.A potential difference V is applied to one end,and the other end is at ground potential.The equivalent resistance of the circuit is

A series circuit consists of a 100 V DC power source,a 100 Ω resistor,and a variable resistor of resistance R,which varies from 0 to 100 Ω.The current in the circuit is

The circuit below contains 4 100-W light bulbs.The emf is 110 V.Which light bulb(s)is(are)brightest?

The circuit below contains 4 100-W light bulbs.The emf is 110 V.Which light bulb(s)is(are)brightest?

At what rate is thermal energy being generated in the 2R-resistor when ε = 12 V and R = 3.0 Ω?

What is the potential difference V_B − V_A when the I = 1.5 A in the circuit segment below?

What is the equivalent resistance between points a and b when R = 12 Ω?

The circuit below contains 5 identical light bulbs.The emf is 110 V.Which light bulb(s)is(are)brightest?

Determine ε when I = 0.50 A and R = 12 Ω.

The circuit below contains three 100-W light bulbs.The emf ε = 110 V.Which light bulb(s)is(are)brightest?

The circuit below contains 3 100-W light bulbs and a capacitor.The emf is 110 V.Which light bulb(s)is(are)brightest? (Assume the capacitor is fully charged. )

A 10-V battery is connected to a 15-Ω resistor and an unknown resistor R,as shown.The current in the circuit is 0.40 A.How much heat is produced in the 15-Ω resistor in 2.0 min?

Determine R when I = 0.20 A and ε = 18 V.