**1. What is the use of Vernier calipers?**

**Answer:** Vernier calipers are used to measure the internal and external diameter and the depth of a vessel with high precision.

**2. How is the screw gauge used to determine the thickness or diameter of a thin sheet/wire?**

**Answer:** The screw gauge measures the thickness or diameter by placing the sheet or wire between its spindle and anvil and rotating the screw until the object is gently secured, then reading the measurement on the thimble and sleeve scale.

**3. Describe the experiment involving a simple pendulum to study energy dissipation.**

**Answer:** The experiment involves plotting a graph between the square of the amplitude and time to observe the dissipation of energy in a simple pendulum.

**4. How do you determine the mass of an object using a metre scale and the principle of moments?**

**Answer:** By balancing the metre scale on a pivot and placing the object at a known distance from the pivot, the mass can be determined using the principle of moments, where the clockwise moment equals the counterclockwise moment.

**5. Explain how to find Young’s modulus of elasticity for a metallic wire.**

**Answer:** Young’s modulus is found by measuring the extension of the wire under different loads and using the formula

where F is the force, L is the original length, A is the cross-sectional area, and ΔL is the extension.

**6. How do you measure the surface tension of water using capillary rise?**

**Answer:** Surface tension is measured by observing the height to which water rises in a capillary tube and applying the formula

where h is the height, ρ is the density, g is the acceleration due to gravity, and r is the radius of the tube.

**7. Describe the method to find the coefficient of viscosity of a liquid using terminal velocity.**

**Answer:** The coefficient of viscosity is determined by measuring the terminal velocity of a spherical object falling through the liquid and using Stokes’ law,

where r is the radius of the sphere, ρ_{s} and ρ_{l} are the densities of the sphere and liquid, g is gravity, and v is terminal velocity.

**8. How can the speed of sound in air be measured using a resonance tube?**

**Answer:** The speed of sound in air is measured by adjusting the length of the air column in the resonance tube until resonance is heard and using the formula

where f is the frequency of the tuning fork and λ is the wavelength.

**9. Explain the method to find the specific heat capacity of a solid by the method of mixtures.**

**Answer:** The specific heat capacity of a solid is found by mixing it with a known mass of water at a different temperature and using the principle of conservation of energy,

**10. How do you determine the resistivity of a material using a metre bridge?**

**Answer:** The resistivity is determined by measuring the resistance of the material with a metre bridge and applying the formula

where R is the resistance, A is the cross-sectional area, and L is the length of the material.

**11. How is the resistance of a wire measured using Ohm’s law?**

**Answer:** The resistance is measured by applying a known voltage across the wire, measuring the current, and using Ohm’s law

**12. Describe how to find the resistance and figure of merit of a galvanometer by the half-deflection method.**

**Answer:** The resistance is found by using a known resistor and adjusting it until the galvanometer shows half the deflection. The figure of merit is the current required to produce one division deflection.

**13. How do you determine the focal length of a convex mirror using the parallax method?**

**Answer:** The focal length is determined by positioning an object and its image at the same position using the parallax method and measuring the distance from the mirror to the object.

**14. How can you plot the angle of deviation vs angle of incidence for a triangular prism?**

**Answer:** By passing a light ray through the prism at various angles of incidence and measuring the corresponding angles of deviation, then plotting these values on a graph.

**15. Describe the method to find the refractive index of a glass slab using a travelling microscope.**

**Answer:** The refractive index is found by measuring the apparent shift in position of a mark seen through the slab and applying the formula

**16. Explain how to plot the characteristic curves of a p-n junction diode in forward and reverse bias.**

**Answer:** By applying varying voltages to the diode and measuring the current in both forward and reverse bias, then plotting the current vs voltage on a graph.

**17. How do you determine the characteristic curves of a Zener diode and find its reverse breakdown voltage?**

**Answer:** By increasing the reverse bias voltage across the Zener diode until breakdown occurs and plotting the current vs voltage to find the breakdown voltage.

**18. How can you identify diodes, LEDs, resistors, and capacitors from a mixed collection?**

**Answer:** By using a multimeter to measure the electrical properties such as resistance, forward voltage drop, and capacitance to identify each component.

**19. How is the focal length of a convex lens determined using the parallax method?**

**Answer:** The focal length is determined by placing an object and moving the lens until a sharp image is formed on a screen, then measuring the distance from the lens to the object.

**20. Describe the procedure to measure the focal length of a concave mirror using the parallax method.**

**Answer:** The focal length is measured by placing an object at a known distance and adjusting the position of the mirror until the object’s image and the object itself are in parallax (coincide), then calculating the distance.