current electricity class 12

The diagram at the right shows two identical resistors - R1 and R2 - placed in a circuit with a 12-Volt battery. If a third resistor (R3), identical to the other two, is added in parallel with the first two, then the overall resistance will ____ and the overall current will ____.

• increase, increase

• decrease, decrease

• increase, decrease

• decrease, increase

A high resistance light bulb and a low resistance light bulb are connected in series to a 6-Volt pack of batteries. Which of the two light bulbs will shine the brightest?

• They will have the same brightness.

• The low-R bulb will shine more brightly.

• The high-R bulb will shine more brightly.

• None of the above

The internal resistance of a cell is the resistance of

• Material used in the cell

• Electrolyte used in the cell

• Electrodes of the cell

• vessel of the cell

The amount of charge flowing through a cross-sectional area of a wire per unit of time is called:

• Voltage

• Power

• Resistance

• Work

• Current

Two resistors R1 = 6 Ω and R2 = 12 Ω are connected in parallel to each other and in series to R3 = 2 Ω. An ammeter measures an electric current of 3 A flowing though resistor R3. What is the net voltage applied to the circuit?

• 6 V

• 12 V

• 18 V

• 24 V

The conductance of a 923Ω resistance is

• 1.08 * 10-3 mho

• 1.08 * 10-4 mho

• 1.02 * 10-3 mho

• 1.02 * 10-4 mho

The algebraic sum of voltages around any closed path in a network is equal to ____________

• Infinity

• 1

• 0

• Negative Polarity

Thicker wires have _______ resistance than thinner wires.

• more
• less
• the same

Which type of current comes from a battery?

• alternating current (AC)
• direct current (DC)

Kirchhoff’s II law for the electric network is based on:

• Law of conservation of charge

• Law of conservation of energy

• Law of conservation of angular momentum

• Law of conservation of mass