Experimental Skills (Physics) · Question 1

In parallax method for the determination of focal length of a concave mirror, the object should always be placed:

1. between the focus (F) and the centre of curvature (C) of the mirror ONLY
2. between the pole (P) and the focus (F) of the concave mirror ONLY
3. at any point beyond the focus (F) of the mirror
4. beyond the centre of the curvature (C) of the mirror ONLY

For the determination of refractive index of glass slab, a travelling microscope is used whose main scale contains 300 equal divisions equal to 15 cm. The vernier scale attached to the microscope has 25 divisions equal to 24 divisions of main scale. The least count (LC) of the travelling microscope is (in cm) :

1. 0.002
2. 0.0025
3. 0.0005
4. 0.001

In the experiment for measurement of viscosity ' ' of given liquid with a ball having radius R, consider following statements. Choose the correct answer from the options given below:

1. C, D and E Only
2. A, B and E Only
3. A, C and D Only
4. B, D and E Only