While using a post office box the keys should be swiched on in the following order ,

the post office box works on the peinclple of :

the post office box works on the peinclple of :

Identify the animals using the following key

What are the maximum and minimum values of unknown resistance X , which can be determined using the post office box shown in the figure?

In a post office box if the position os the cell and the galvenometer are interchangd, then the:

In a post office box if the position os the cell and the galvenometer are interchangd, then the:

While using an electric bulb, the reflection for street lighting should be from

What important factors should be kept in mind while using this method?