Quiz — BAS151

Q1. Newton's rings are formed between:

A. Two plane glass plates B. A plano-convex lens and a flat glass plate C. Two convex lenses D. A prism and a mirror

Q2. In the reflected system, the centre of the Newton's rings pattern is:

A. Bright B. Dark C. Coloured red D. Invisible

Q3. The diameter of the nth dark ring in Newton's rings (reflected light) is proportional to:

A. n B. √n C. n² D. 1/n

Q4. A plot of D_n² vs n for Newton's rings should be:

A. A parabola B. A straight line C. A circle D. Exponential

Q5. The light source commonly used in the Newton's rings experiment is:

A. White light bulb B. Sodium lamp (monochromatic) C. Laser pointer only D. UV lamp

Q6. In Fresnel's biprism experiment, the separation of virtual sources d is found using the:

A. Direct vision method B. Displacement method with a convex lens C. Polarimeter method D. Hall effect method

Q7. Fringe width in the biprism experiment is given by:

A. β = λD/d B. β = λd/D C. β = d/λD D. β = D/λd

Q8. A biprism produces two coherent virtual sources by the process of:

A. Diffraction B. Refraction C. Total internal reflection D. Polarization

Q9. A polarimeter is used to measure:

A. Wavelength of light B. Specific rotation of an optically active solution C. Refractive index of glass D. Focal length of a lens

Q10. Specific rotation of a sugar solution generally depends on:

A. Concentration, length of tube, wavelength and temperature B. Only the colour of light C. Only the size of the container D. Atmospheric pressure only

Q11. A plane transmission grating spectrometer must first be adjusted for:

A. Divergent rays B. Parallel rays (Schuster's method) C. Convergent rays only D. Random incidence

Q12. The grating equation for principal maxima is:

A. (a+b) sinθ = nλ B. a sinθ = nλ C. (a+b) cosθ = nλ D. nλ = a - b

Q13. The 'grating element' (a+b) refers to:

A. Number of lines per cm B. Sum of slit width and opaque spacing C. Diffraction angle D. Order of spectrum

Q14. Polarization by simple reflection is best observed near:

A. The critical angle B. Brewster's angle C. 0° incidence D. 90° incidence only

Q15. At Brewster's angle, the reflected light is:

A. Completely unpolarized B. Completely (or mostly) plane polarized C. Circularly polarized D. Absorbed entirely

Q16. A single-slit diffraction experiment with a He-Ne laser is used to determine:

A. The laser's power B. The wavelength of laser light C. The laser's coherence length only D. The slit material

Q17. Carey Foster's bridge is primarily used to:

A. Measure very high resistances only B. Compare two nearly equal low resistances precisely C. Generate AC voltage D. Measure capacitance

Q18. Resistivity from a wire's resistance is calculated using:

A. ρ = RL/A B. ρ = RA/L C. ρ = R/AL D. ρ = A/RL

Q19. The purpose of interchanging resistance arms in Carey Foster's bridge is to:

A. Increase the current B. Eliminate end-corrections/contact resistances C. Reduce the wire's length D. Change the galvanometer sensitivity

Q20. A tangent galvanometer measures current by comparing it to:

A. The Earth's horizontal magnetic field B. Atmospheric pressure C. The speed of light D. Gravitational acceleration

Q21. Stefan's law relates radiated power to:

A. The square of temperature B. The fourth power of absolute temperature C. The cube root of temperature D. Temperature linearly

Q22. Verifying Stefan's law electrically typically uses the relation between filament resistance and:

A. Filament length only B. Filament temperature C. Ambient humidity D. Filament colour

Q23. A potentiometer is used to calibrate an ammeter/voltmeter because it:

A. Draws current from the circuit under test B. Measures potential difference without drawing current at balance C. Only works with AC D. Cannot give accurate null readings

Q24. In the Hall effect experiment, the Hall voltage develops:

A. Along the direction of current flow B. Transverse to both current and magnetic field C. Parallel to the magnetic field D. Opposite to the applied voltage

Q25. Hall coefficient R_H is given by:

A. V_H t /(IB) B. IB/(V_H t) C. V_H/(I B t) D. IBt/V_H

Q26. The sign of the Hall voltage tells us:

A. The magnitude of current only B. Whether the semiconductor is n-type or p-type C. The applied magnetic field strength only D. The sample's melting point

Q27. Carrier mobility from Hall data is calculated as:

A. μ = σ / R_H B. μ = σ R_H C. μ = R_H / σ D. μ = σ + R_H

Q28. Band gap of a semiconductor from resistance–temperature data is obtained from the slope of a plot of:

A. R vs T B. ln R vs 1/T C. R vs 1/T² D. ln R vs T

Q29. As temperature increases, resistance of an intrinsic semiconductor generally:

A. Increases B. Decreases C. Stays constant D. Becomes infinite

Q30. A hysteresis loop for a ferromagnetic material shows lag between:

A. Voltage and current B. Magnetising field H and flux density B C. Temperature and pressure D. Resistance and length

Q31. The area enclosed by a B–H hysteresis loop represents:

A. Energy dissipated per cycle as heat B. Total magnetic flux C. The material's density D. Electrical resistivity

Q32. Retentivity refers to:

A. The field required to demagnetize a material completely B. The residual magnetism when H is reduced to zero C. The maximum current a coil can carry D. The specific heat of iron

Q33. Coercivity refers to:

A. Residual magnetism at H = 0 B. The reverse field required to reduce B to zero C. The saturation flux density D. The permeability of free space

Q34. Ballistic galvanometer measurements are used to determine quantities related to:

A. Steady current only B. Charge (a transient quantity), via the first swing/throw C. Voltage only in AC circuits D. Resistance directly by Ohm's law

Q35. The coefficient of viscosity of a liquid can be found using Stokes' method by measuring:

A. The refractive index of the liquid B. The terminal velocity of a small sphere falling through it C. The boiling point of the liquid D. The colour of the liquid

Q36. In Stokes' method, terminal velocity is reached when:

A. Acceleration is maximum B. Net force on the sphere becomes zero (drag balances weight minus buoyancy) C. The sphere stops completely D. Viscosity becomes zero

Q37. Numerical aperture of an optical fibre determines:

A. The core's colour B. The light-gathering (acceptance) ability of the fibre C. The fibre's mechanical strength only D. The cladding's melting point

Q38. Fibre attenuation is usually expressed in units of:

A. Watts B. Decibels per kilometre (dB/km) C. Newtons D. Joules per second

Q39. The 'leakage method' for high-resistance measurement relies on:

A. Rate of discharge of a charged capacitor through the resistance B. AC bridge balance C. Direct ohmmeter reading D. Thermocouple EMF

Q40. Magnetic susceptibility of a paramagnetic solution is typically measured using:

A. A Quincke's tube method B. A polarimeter C. A spectrometer D. A Carey Foster bridge

Q41. A travelling microscope is primarily used in optics experiments to:

A. Generate monochromatic light B. Measure small distances precisely (e.g., ring diameters, fringe widths) C. Filter unwanted wavelengths D. Rotate the plane of polarization

Q42. Parallax error in a travelling-microscope reading is minimized by:

A. Reading quickly without checking alignment B. Ensuring the cross-wire and the image are in the same focal plane C. Using white light only D. Increasing the magnification indefinitely

Q43. In the biprism experiment, increasing the distance D between source and eyepiece will:

A. Decrease fringe width B. Increase fringe width C. Not affect fringe width D. Eliminate the fringes

Q44. Before starting the diffraction grating experiment, the spectrometer telescope must be focused for:

A. Near objects B. Parallel rays / infinity C. Only red light D. Only violet light

Q45. The precaution of avoiding backlash error applies mainly to:

A. Screw-gauge and travelling microscope readings B. Voltmeter readings only C. Sound level readings D. Colour perception tests

Q46. A null-deflection method (as in a bridge or potentiometer) is preferred because it:

A. Requires no calibration and avoids loading errors B. Always gives faster results C. Only works with AC D. Needs no galvanometer

Q47. Which experiment listed in the Physics Lab syllabus directly determines a semiconductor's majority carrier type?

A. Newton's rings B. Hall effect experiment C. Biprism experiment D. Viscosity experiment

Q48. Which of the following is NOT typically recorded in a standard lab report?

A. Aim and apparatus B. Observation table and calculations C. Result and precautions D. The lab instructor's personal opinions

Q49. The minimum number of experiments to be performed in BAS151, with at least four from each group, is:

A. Any five B. Any ten C. All experiments listed D. Only two

Q50. Precision of a measuring instrument such as a screw gauge or travelling microscope is limited by its:

A. Colour B. Least count C. Weight D. Price

BAS15150-Question MCQ Quiz