इ The wavelength of visible spectrum is :

(4) 400-700 ‏سد‎ 18) 300-480 ௩௩
)0 680-880 nm (D) 280-410 nm
44. In ECG waveform repolarization of ventricles is represented by :
(A) Pwave (B) QRS complex
(€) Twave D) Uwave
45. 1N4001 is the name of a semiconductor device. Identify it :
(ಹ) 7 (B) SCR
(0 Transistor (D) Diode
46. The principle of X-ray production at coolidge tube depends on :

(வி Conversion of potential energy into electromagnetic radiation
(B) Conversion of thermal energy in to electromagnetic radiation
(C) Conversion of kinetic energy into electromagnetic radiation

(D) Conversion of mechanical energy into electromagnetic radiation

47. The External magnetic field in 1.5T MRI machine is generated using :
(A) A permanent magnet (18) An electromagnet
(C) A superconducting magnet (D) All the above

48. Average velocity of ultrasound in hone is :
(A) 1540 m/s
)0 330m/s

) 77701
(D) 220m/s

49. Which of the following instrument uses ultrasound for its operation?
(B) Magnetoencephalograph
(D) Echoencephaloscope

(A) Electroencephalograph
(0) Electromyograph

50. When transistor 15 used as an amplifier?
(A) Emitter-base junction is reverse biased and collector-base junction is forward
biased
(B) Emitter-base junction is forward biased and collector-base junction is reverse
biased
(C) Emitter-base junction and collector-base junction are reverse biased
(D) Emitter-base junction and collector-hase junctior are forward biased

51. A carbon resistor having silver colour in fourth band has a tolerance value of +/~ 500, Find
the value of the resistor :

(ക) 11൧
(0 2KQ

(7)
)

1.5೫೧
5000

51/2015 8 A