HEAT (PROBLEMS) Problem 11.1. i) The normal body temperature is 98.4 F. What is this temperature on Celsius scale? ii) At what temperature do the Fahrenheit and Celsius scales coincide. Problem 11.2. A steel rod has a length of exactly 0.2cm at 30°C. What w…
Continue ReadingPhysics 12th Class Problems 11. HEAT 12. ELECTROSTATICS 13. CURRENT ELECTRICITY 14. MAGNETISM AND ELECTROSTATICS 15. ELECTRICAL MEASURING INSTRUMENTS 16. ELECTROMAGNETIC WAVES AND ELECTRONICS 17. ADVENT OF MODERN PHYSICS …
Continue ReadingProblem 10.15. Two converging lenses are 25 cm part. Focal length of each is 10 cm. An object is placed in front of one lens at 50 cm. Find the distance between the object and the final image? Data Focal length of each lens f1= f2 =f =10cm Distance between le…
Continue ReadingProblem 10.14. A convex lens forms image of an object on a fixed screen 20 cm from the lens. On moving the lens 60 cm towards the object, the image is again formed on the screen. What is the focal length of the lens?
Continue ReadingProblem 10.9. A compound microscope has a 12 mm focal length objective and a 75 mm focal length eye piece, and the two lenses are mounted 200 mm apart. If the final image is 225 mm from the eye piece, what is the magnification produced? Data Focal length of o…
Continue ReadingProblem 10.8. Find the distance at which an object should be placed in front of a convex lens of focal length 10 cm to obtain an image of double its size? Data Focal length of lensf=10cm Image size =2× object size K/a magnificent m =2 To find.... Object dist…
Continue ReadingProblem 10.7. Moon light passes through a converging lens of focal length 19 cm, which is 20.5 cm from a second converging lens of focal length 2 cm. Where is the image of the moon produced by the lens combination? Data Focal length of first lens f1 =19cm Foc…
Continue ReadingProblem 10.6. Two lenses are in contact, a converging one of focal length 30cm and a diverging one of focal length 10cm. What is the focal length and power of the combination? Data Focal length of first lens.f1 =30cm Focal length of 2nd lens f2 = -10cm To fi…
Continue ReadingProblem 10.5. A parallel light beam is diverged by a concave lens of focal length -12.5cm and then made parallel once more by a convex lens of focal length 50cm. How far are the two lenses apart. Data Focal length of first lens.f1 = -12.5cm Focal length of 2…
Continue ReadingProblem 10.4. A converging lens of focal length 20 cm is placed in front of a converging lens of focal length 4 cm. What is the distance between the lenses if parallel rays entering the first lens leave the second lens as parallel rays? Data Focal length of …
Continue ReadingProblem 10.3. Two converging lenses of focal lengths 40 cm and 50 cm are placed in contact. What is the focal length of this lens combination? What is the power of the combination in diopters? Data . Focal length of first lens.f1 =40cm Focal length of 2nd len…
Continue ReadingProblem 10.2. A convex lens has a focal length of 10 cm. Determine the image distances when an object is placed at the following distances from the lens. (50 cm, 20 cm, 15 cm, 10 cm and 5 cm). . A convex lens has a focal length of 10 cm. Determine the image d…
Continue ReadingGEOMETRICAL OPTICS (PROBLEMS) Problem 10.1. An object 4 cm tall is placed near the axis of a thin converging lens. If the focal length of the lens is 25 cm, where will the image be formed and what will be the size of the image? Sketch the principal ray diag…
Continue ReadingProblem 9.8. How far apart are the diffracting planes in a NaCl crystal for which X-rays of wavelength 1.54A make a glancing angle of 15° - 54' in the 1st order? Data Glancing angle 0= 15°54' =15+54/60 =15 .9° Wavelength 1.54Av=1. 54×10-¹⁰m M =1 To f…
Continue ReadingProblem 9.9. A parallel beam of X-rays is diffracted by rocksalt crystal the 1st order maximum being obtained when the glancing angle of incidence is 6 degree and 5 minutes. The distance between the atomic planes of the crystal is 2.8 x 10^-10m. Calculate the…
Continue ReadingProblem 9.7. Newton's rings are formed between a lens and a flat glass surface of wavelength 5.88 × 10^−7m. If the light passes through the gab at 30° to the vertical and the fifth dark ring is of diameter 9 mm. What is the radius of the curvature of the …
Continue ReadingProblem 9.1. How many fringes will pass a reference point if the mirror of a Michelson's interferometer is moved by 0.08 mm. The wavelength of light used is 5800Å. Data Displacement of mirror x=0.08mm =0.08× 10-³m Wavelength of light speed =5800=5800×10-¹…
Continue ReadingProblem 8.9. An ambulance travels down a highway at a speed of 75 mi/h. Its siren emits sound at a frequency heard by a person in a car traveling at 55 mi/h in the opposite direction as the car approaches the ambulance and as the car moves away from the ambul…
Continue ReadingProblem 8.5. Calculate the speed of sound in air at atmospheric pressure P = 1.01 x 10°N/m?, taking λ = 1.40 and p = 1.2kg/m3.
Continue ReadingProblem 8.4. A standing wave is established in a 120 cm long string fixed at both ends. The string vibrates in four segments when driven at 120 Hz (a) Determine the wavelength (b) What is the fundamental frequency?
Continue Reading
