Collection of Problems received from Class 12 Physics

These problems were posted by Geena. Hope that we will be able to post the answers to these questions soon; each in a separate post. By the time visitors can attempt to post their answers as comments to this post. (Only selected posts will be published)
 
Please note that the answers are not published until the […]

A few problems from Current electricity

1. A carbon resistor of 47 k ohms is to be marked in the colour code . Write the sequence of colours . 2. A toaster produces more heat than a light bulb when connected in parallel to the 220 V mains . Which of the two has greater resistance ? 3. A 0- 50…… Continue reading A few problems from Current electricity

Why ordinary ammeter cannot measure AC?

Ac changes its direction frequently and therefore the ordinary ammeter which is just a galvanometer with a shunt, tends to respond to the magnitude and direction of the instantaneous values of current and in effect it will not show any deflection. Ac is measured using hot wire ammeter, which is based on the heating effect…… Continue reading Why ordinary ammeter cannot measure AC?