An experiment demonstrating the dependence of current on voltage is shown on two circuits that differ in current sources and lamps, but having a current of the same magnitude.
The voltage created by the battery is much less than the voltage of the city network, therefore, with the same amperage, the lamp in the battery circuit gives less light and heat.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.