Consider the following statements about a solenoid.

1. The magnetic field strength in a solenoid depends upon the number of turns per unit length in the solenoid.

2. The magnetic field strength in a solenoid depends upon the current flowing in the wire of the solenoid.

3. The magnetic field strength in a solenoid depends upon the diameter of the solenoid.

Which of the statements given above are correct?

Light year is a unit of measurement of

The focal length of the objective lens of a telescope is 50 cm. If the magnification of the telescope is 25, then the focal length of the eyepiece is

Which one of the following force is non-central and non-conservative?