Physics Fully solved questions with complete explanation for written test, interview, competitive exams and entrance test. This section is very useful for those who are preparing for competitive exams such as Written test of IT companies,Bank Exams, CAT Exams, GATE Exams, Railway Exams, SSC, UPSC, Defence and many more.

Q. When a metal is heated it emits predominantly

  • A) electrons
  • B) protons  
  • C) positrons  
  • D) neutrons
Q. Thermonic emission was discovered by

  • A) Thomas Edison
  • B) lee de forest
  • C) fleming
  • D) Rutherford
Q. work function is generally expressed in

  • A) electron volt
  • B) joule
  • C) newton
  • D) gauss
Q. the saturation current in a diode can be increased by

  • A) lower plate potential
  • B) raising plate potential
  • C) increasing cathode temperature
  • D)  decreasing cathode temperature
Q. The saturation current in diode valve depends upon

  • A) plate voltage
  • B) temperature of the filament
  • C) neither a nor b
  • D) both a and b
Q. in a halfwave rectifier the rms valve of the a.c component of the wave is

  • A) greater than d.c value
  • B) less than d.c value
  • C) equal to d.c value
  • D) zero
Q. when a charged particle moves in a transverse magnetic field, it path of motion is

  • A) parabolic
  • B) circular
  • C) elliptical
  • D) linear
Q. an electron moves with a constant velocity V parallel to the direction of uniform magnetic field B. the force experienced by the electron is

  • A) BeV
  • B) eV/B
  • C) B/eV
  • D) zero  
Q. An electron of mass M kg and charge ‘e’ columbs travel from rest through a potential difference of V volts. The field energy of electron in joule is

  • A) MeV
  • B) eV/M
  • C) eV
  • D) e/V
Q. A charged particle moves through a magnetic field perpendicular to it. The energy of the particle

  • A) increases
  • B) decreases
  • C) remains unchanged
  • D) first increase and then decreases
Today's Challenging Question
Q. Ajay & Bimal can do a price of work in 10 days, Bimal & Chetan can do in 15 days and Chetan and Ajay in 20 days. They work together for 6 days and then Ajay leaves and now Bimal & Chetan work together for 4 more days. If Bimal leaves, how long will Chetan take to finish the work?
A) 12 days
B) 10 days
C) 16 days
D) none
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