Measurement of D.C. voltage and current by multimeter

Aim: The aim of the experiment is to measure DC voltage and current using a multimeter.

Apparatus:

1. Multimeter: A digital or analog multimeter capable of measuring DC voltage and current.

2. Test leads: Detachable probes that come with the multimeter, typically red and black in color.

3. Power source: A DC power source or a circuit with a DC power supply.

Theory:

- DC Voltage Measurement: The multimeter measures the potential difference between two points in a circuit. In DC voltage measurement, the multimeter applies a small known voltage across its probes and measures the voltage drop across the component or circuit being tested. The result is displayed in volts (V).

- DC Current Measurement: The multimeter measures the flow of electric current in a circuit. In DC current measurement, the multimeter is connected in series with the circuit being tested. It measures the current passing through it and displays the result in amperes (A).

Procedure:

1. Ensure that the multimeter is set to the appropriate mode for DC voltage and current measurements.

2. Connect the black probe to the COM (common) port of the multimeter.

3. Connect the red probe to the appropriate port based on the measurement being performed (VΩmA for voltage, 10A for current).

4. For voltage measurement:

a. Ensure that the circuit or component is disconnected from the power source.

   b. Touch the black probe to the ground or negative terminal of the circuit/component.

   c. Touch the red probe to the positive terminal of the circuit/component.

   d. Read the voltage value displayed on the multimeter's screen.

5. For current measurement:

   a. Ensure that the circuit is disconnected from the power source.

   b. Open the circuit and insert the multimeter in series with the component to measure the current.

   c. Connect the red probe to the positive side of the circuit and the black probe to the negative side.

   d. Make sure the current flows through the multimeter without exceeding its selected current range.

   e. Read the current value displayed on the multimeter's screen.

Results:

- The multimeter will display the measured DC voltage in volts (V) for voltage measurements.

- The multimeter will display the measured DC current in amperes (A) for current measurements.

Remember to exercise caution when working with electricity and follow safety procedures to prevent any accidents or damage to the equipment.