Voltmeter range

We have a voltmeter which in the original set measures voltage to 10V. Calculate the size of the ballast resistor for this voltmeter, if we want to measure the voltage up to 50V. Voltmeter's internal resistance is 2 kiloohm/Volt.

Correct answer:

R2 =  80000 Ω

Step-by-step explanation:

U1=10 V U2=50 V  R1=20 1000=20000 Ω I=U1R1=1020000=12000=0.0005 A  U3=U2U1=5010=40 V  U3=I R2  R2=U3/I=40/0.0005=80000 Ω

We will be pleased if You send us any improvements to this math problem. Thank you!


Related math problems and questions:

  • Resistance of the resistor
    Elektrárna_1 The resistor terminals have a voltage of 20 V and a current of 5 mA is passed through. What is the resistance of the resistor?
  • Effective and mean voltage
    serial-parallel A voltage divider consisting of resistors R1 = 103000 Ω and R2 = 197000 Ω is connected to the ideal sine wave voltage source, R2 is connected to a voltmeter which measures the mean voltage and has an internal resistance R3 = 200300 Ω, the measured value i
  • Lowest voltage
    inSeries Three resistors with resistors R1 = 10 kΩ, R2 = 20 kΩ, R3 = 30 kΩ are connected in series and an external voltage U = 30 V is connected to them. On which resistor is the lowest voltage?
  • Resistance - ohms
    resistor_2 If the resistance of the first resistor is 300 ohms and the resistance of the second resistor is 100 ohms. What is the resulting resistance?
  • Closed circuit
    voltemeter In a closed circuit, there is a voltage source with U1 = 12 V and with an internal resistance R1 = 0.2 Ω. The external resistance is R2 = 19.8 Ω. Determine the electric current and terminal voltage.
  • The bulbs
    resistor_6 The bulbs are connected serially two bulbs and one resistor. Each bulb has a resistivity of 100 ohms and resistor of 60 ohms The voltage source in the circuit is 24 volts. Do you know what voltage to measure on individual appliances?
  • Resistance
    Rezistor_2 A resistor having an electrical resistance of 1.5 k ohms passes an electrical current of 0.1 A. Calculate what voltage is between the terminals of the resistor.
  • Coils of transformer
    voltemeter The primary coil of the transformer has 1100 turns and is connected to a voltage of 220V. How many turns does the secondary coil have when the voltage on it is 55 V? Find the transformation ratio and decide what kind of transformation.
  • Resistance
    bulb_1 Determine the resistance of the bulb with the current 200 mA and is in a regular lamp (230V).
  • Current in the conductor
    ohms-law Calculate the current in the conductor (in mA) if it is connected to a 4.5 V voltage source and its resistance is 20 (ohm).
  • The transformer
    transformator The primary coil of the transformer has 1100 turns and is connected to a voltage of 220 V. How many turns does the secondary coil have when it has a voltage of 55 V? Determine the transformation ratio and decide what the transformation is.
  • Mains voltage
    bulb How much electric current flows through the appliance with a resistance of 40kΩ, which is connected to the mains voltage (230 V)?
  • Transformer
    trafo Solve the textbook problems - transformer: a) N1 = 40, N2 = 80, U2 = 80 V, U1 =? b) N1 = 400, U1 = 200 V, U2 = 50 V, N2 =?
  • The bulb
    bulbs The bulb has a reading of 6V-0.05 A, what current flows through the bulb if we connect it to a cell with a voltage of 12V?
  • Electric work
    bulb Calculate the work done by the electric forces passing the current of 0.2 A through the bulb in 10 minutes if the bulb is connected to a 230 V power supply.
  • The resistance
    resistor What is the resistance of an aluminum wire 0.2 km long and 10 mm in diameter?
  • Filament of bulb
    bulb _1 The filament of bulb has a 1 ohm resistivity and is connected to a voltage 220 V. How much electric charge will pass through the fiber when the electric current passes for 10 seconds?