The magnetic lines of force are closer why?
The magnetic lines of force are closer at the poles as the result the force is stronger at the poles but when they are away from the poles, the force is comparatively less strong.
Ammeter is connected in series and voltmeter is connected parallel in an electric circuit, why?
Ammeter is the device used to measure the electric current. So, total current flowing through the circuit must pass through the ammeter. Therefore, it is connected in series. While voltmeter is the device used to measure the potential difference between two ends. Therefore, voltmeter is parallel to measure the potential difference across two ends.