Electricity 3

  1. Which one of the circuits shown in the diagram below can be used to determine the resistance of \(R\)? 

    diagram with 4 circuits

    (A)  I 
    (B)  II 
    (C)  III 
    (D)  IV 

    D is correct


     
  2. A car's starter motor draws a current of \(100\; A\) at \(12,0\; V\) when starting the engine. The mechanical power required to turn the engine is \(960\; W.\) At what rate is energy from the battery converted to non-mechanical forms of energy? 

    (A)  \(240\; W\) 
    (B)  \(960\; W\) 
    (C)  \(1200\; W\) 
    (D)  \(1440\; W\) 

    A is correct


     
  3. In the circuit shown below one of the bulbs blew. The result was that all bulbs stopped glowing. Which bulb blew? 

    diagram of circuit showing three bulbs

    (A)  bulb a 
    (B)  bulb b 
    (C)  bulb c 
    (D)  bulb d 

    C is correct


     
  4. Three resistors are connected to a battery as shown in the diagram. At which point in the circuit is the current the smallest?

    diagram of circuit with three resistors and a battery

    (A)  a 
    (B)  b 
    (C)  c 
    (D)  d 

    C is correct


     
  5. In the circuit shown, the resistance of the ammeter, the battery and the connecting wires are negligible. The voltmeter has a very high resistance. The ammeter reads \(1,5\; A.\) What is the reading on the voltmeter?

    diagram of a circuit with battery, ammeter and voltmeter.

    (A)  \(4\; V \)
    (B)  \(6\; V\) 
    (C)  \(8\; V\) 
    (D)  \(12\; V\) 

    B is correct


     
  6. Two resistors are connected in parallel as shown in the diagram. The current flowing through the ammeter is:

    diagram of circuit with two resistors connected in parallel

    (A)  \(0,6\; A\) 
    (B)  \(1,5\; A\) 
    (C)  \(2,5\; A\) 
    (D)  \(14,4\; A\) 

    C is correct


     
  7. Consider the circuit shown to the right. If switch \(S\) is closed, the readings on the voltmeter and ammeter will change as follows:  

    diagram of circuit with a switch
     
    Answer voltmeter reading ammeter reading
    (A) becomes zero remains the same
    (B) becomes zero increases
    (C) remains the same decreases
    (D) decreases increases
       

    B is correct

     
  8. The circuit below shows two identical bulbs, \(L\) and \(M,\) which are connected to a battery and a variable resistor \(R.\) How will the brightness of the bulbs be affected if the resistance of \(R\) is increased?    

    diagram of circuit with 2 bulbs and a bettery
     
    Answer Bulb L Bulb M
    (A) dimmer brighter
    (B) dimmer dimmer
    (C) dimmer the same
    (D) brighter the same
       

    A is correct

     
    The battery in the circuit has an internal resistance r and an emf E. The resistance of the ammeter and the conductors is negligible and the voltmeter has a high resistance

    The information given refers to questions 9 and 10: 

    The battery in the circuit has an internal resistance \(r\) and an emf \(E.\) The resistance of the ammeter and the conductors is negligible and the voltmeter has a high resistance



     
  9. When the switch \(S\) is closed, the … 
     
    Answer Voltmeter reading Ammeter reading
    (A) decreases decreases
    (B) decreases increases
    (C) increases decreases
    (D) increases increases
     

    B is correct


     
  10. When the switch \(S\) is closed the power in the resistors \(R_1\) and R2 … 
     
    Answer Power in \(R_1\) Power in \(R_2\)
    (A) decreases decreases 
    (B) decreases increases
    (C) increases decreases
    (D) increases increases

    C is correct