Experimental Skills (Physics)

To compare EMF of two cells using potentiometer the balancing lengths obtained are 200 cm and 150 cm. The least count of scale is 1 cm. The percentage error in the ratio of EMFs is

1. 1.75
2. 1.55
3. 1.17
4. 1.65

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

In finding out refractive index of glass slab the following observations were made through travelling microscope 50 vernier scale divisions = 49 MSD; 20 divisions on main scale in each cm For mark on paper MSR = 8.45 cm, VC = 26 For mark on paper seen through slab MSR = 7.12 cm, VC = 41 For powder particle on the top surface of the glass slab MSR = 4.05 cm, VC = 1 (MSR = Main Scale Reading, VC = Vernier Coincidence) Refractive index of the glass slab is :

1. 1.52
2. 1.35
3. 1.24
4. 1.42

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of 1/ vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is 10-1 A/division. [The source has emf 2 V] [figure]