Power consumption of a light bulb with Cobra SMARTsense

Principle

The incandescent lamp is a classic example of a non-ohmic conductor. Due to the stronger oscillation of the lattice atoms at higher temperatures, the resistance of the incandescent lamp increases with increasing current. This is reflected in the non-linear curve of the current-voltage characteristic.

Benefits

• Particularly comprehensible and didactically prepared description of the experiment (reference to everyday life, etc.) incl. protocol questions.
• Future-oriented teaching: Integration into digital science lessons with tablets or smartphones.
• Increased motivation among students through use of the intuitive measureAPP.
• Increased media literacy.
• No additional cable connections between the modules necessary - clearer and faster set-up.
• contact safety due to puzzle-like interlocking modules.
• Hard gold-plated, corrosion-resistant contacts
• Double learning success: electrical circuit diagram visible on the upper side and real components on the lower side

Tasks

The incandescent lamp is connected in series with an ammeter. A voltmeter is used to simultaneously measure the voltage drop across the incandescent lamp. The students measure the current-voltage characteristic of an incandescent lamp.

Learning Objectives

The students should recognize that the current-voltage characteristic of an incandescent lamp is non-linear and that incandescent lamps are therefore non-resistive conductors.