Test on Electrical Measurements and Experimental Physics

Question 1: Before starting an experiment with electrical devices, one must plan and build the circuit using a circuit diagram.

A. Ano

B. Ne

Explanation: The study materials state that 'Before you get cracking on an experiment involving any kind of electrical devices, you have to plan and build your circuit using a circuit diagram.'

Question 2: What is the primary purpose of knowing circuit symbols before engaging in an experiment with electrical devices?

A. To ensure the experiment is conducted safely without electrical hazards.

B. To correctly plan and build the circuit without being stumped.

C. To understand the theoretical principles behind the electrical devices.

D. To calculate the expected current and voltage values in the circuit.

Explanation: The study materials state, 'Make sure you know all of the circuit symbols on page 179 so you're not stumped before you've even started.' This indicates that knowing the symbols is essential for correctly planning and building the circuit without encountering initial difficulties.

Question 3: When using a multimeter to measure potential difference, the dial should be turned to 'A'.

A. Ano

B. Ne

Explanation: To find the current, the port labeled 'A' or 'mA' is used, and the dial on the multimeter should be turned to 'A' to measure current in amps. The study materials state that if you want to find potential difference, make sure the red wire is plugged into the port that has a 'V', but it does not specify turning the dial to 'A' for potential difference; 'A' is specifically mentioned for current measurement.

Question 4: Voltmeters are connected in parallel across the component being tested to measure potential difference.

A. Ano

B. Ne

Explanation: The study materials state: "Connect the voltmeter in parallel (p.184) across the component you want to test."

Question 5: When connecting an analogue or digital voltmeter, which of the following statements is true regarding its connection and associated wires?

A. Voltmeters should be connected in series with the component to be tested.

B. The red wire is for the positive connection, and the black wire is for the negative connection.

C. The wires should be connected to the red and black coloured ports on the voltmeter.

D. Voltmeters measure current when connected correctly.

Explanation: According to the study materials, voltmeters connect in parallel, not in series, across the component you want to test, making the first option incorrect. The materials state, 'The wires that come with a voltmeter are usually red (positive) and black (negative). These go into the red and black coloured ports on the voltmeter,' confirming that the red wire is positive and black is negative, and they connect to the corresponding ports. Voltmeters measure potential difference, not current, making the fourth option incorrect.