Description : The central region of transistor is called (a) Base (b) emitter (c) collector (d) neutral
Last Answer : (b) emitter
Description : Current gain of a transistor which has collector current of 10 mA and a base current of 40 micro Ampere is: (a) 25 (b) 250 (c) 2500 (d) 25000
Last Answer : b) 250
Description : In a transistor, the conventional current flows from base to emitter. The transistor is (a) NPN (b) PNP (c) FET (d) None of these
Last Answer : (a) NPN
Description : A part of transistor which is heavily doped to produce large number of majority carriers is (a) Emitter (b) Base (c) Collector (d) any of above
Last Answer : (a) Emitter
Description : In the transistor schematic symbol, the arrow ________ (a) located on emitter (b) located on base (c) located on collector (d) points from north to south
Last Answer : a) located on emitter
Description : For normal operation of a transistor, the collector base junction is kept (a) Unbiased (b) forward biased (c) reverse biased (d) none
Last Answer : (c) reverse biased
Description : The operation of a transistor requires ______ (a) Emitter is heated (b) base is heated (c) collector be heated (d) none of above
Last Answer : (d) none of above
Description : In n-p-n transistor, p works as ________ (a) Collector (b) emitter (c) base (d) any of above
Last Answer : c) base
Description : A current of 5.8 A flows through a 0.25 m long straight conductor which is kept perpendicular in a region of uniform magnetic field of 3.7 T . The force on conductor is a) 5.4 N b) 2.4 N c) 3.4 N d) 6.4 N
Last Answer : a) 5.4 N
Description : A proton having mass m and charge q is projected into a region having a perpendicular magnetic field. The angle of deviation of proton when it comes out of the region with mv √2 qB ⁄ is a) π/3 b) π/4 c) π/6 d) 2 π/3
Last Answer : b) π/4
Description : The emitter of a transistor is doped the heaviest because it: (a) Acts as a supplier of charge carriers (b) Dissipates maximum power c) has a large resistance (d) has a small resistance
Last Answer : (a) Acts as a supplier of charge carriers
Description : In p-n-p transistor, collector current is (a) Equal to emitter current (b) slightly less than emitter current (c) greater than emitter current (d) any of above
Last Answer : (c) greater than emitter current
Description : Which is the most important building block of electronic devices? (a) Diode (b) p-n junction (c) transistor (d) rectifier
Last Answer : b) p-n junction
Description : The potential barrier for germanium is _______ (a) 0.6 V (b) 0.2 V (c) 0.3 V (d) 0.5 V
Last Answer : (c) 0.3 V
Description : he substances of conductivity of the order of 10–6 – 10–4 (m)–1 are : a) Insulators b) Super conductors c) Semiconductors d)Good conductors
Last Answer : d)Good conductors
Description : Key point for its proper functioning of base region in a transistor depends upon the thickness of the base Why ?
Last Answer : Base region in a transistor controls the current. The majority charge carriers supplied by the emitter do not combine in the same region due to its thin size and light doping and most of them pass on to the collector. This is the key point for its proper functioning.
Description : In a transistor, the base is _______. (1) an insulator (2) a conductor of low resistance (3) a conductor of high resistance (4) an extrinsic semiconductor
Last Answer : (2) a conductor of low resistance Explanation: A transistor is a semiconductor device used to amplify and switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit.
Description : In the phenomenon of Laser production, atom can reside in the excited state only for a) 10-6 s b) 10-7 s c) 10-8 s d) 10-9 s
Last Answer : c) 10-8 s
Description : Which series lies in the Ultraviolet region? a) Lyman series b) Paschen series c) Brackett serie d) Balmer series
Last Answer : a) Lyman series
Description : Three spectral series, paschen series, Brackett series, Pfund series are found in the a) ultraviolet region b) visible region c) infrared region d) a & b region
Last Answer : c) infrared region
Description : The region where the Lyman series contains the wavelength 1∕ λ = RH [1/ 12 – 1/ n2 ] is a) visible region b) infrared region c) ultraviolet region d ) none of these
Last Answer : c) ultraviolet region
Description : The only series which lies in the visible region of the electromagnetic spectrum is a) Paschen series b) Lyman series c) Balmer series d) Pfund series
Last Answer : b) Lyman series
Description : The radiations emitted by human body lies in a) Infrared region b) Ultraviolet region c) Visible region d) None of the above
Last Answer : a) Infrared region
Description : Depletion region of a junction is formed _________ (a) during the manufacturing process (b) under forward bias (c) under reverse bias (d) when temperature varies
Last Answer : (a) during the manufacturing process
Description : The potential difference set up across the depletion region is called (a) Absolute potential (b) neutral potential (c) reverse potential (d) potential barrier
Last Answer : (d) potential barrier
Description : Depletion region carries _________ (a) +ve charge (b) –ve charge (c) no charge (d) all of above
Last Answer : (c) no charge
Description : N-type region has majority charge carriers as (a) Holes (b) protons (c) neutrons (d) electrons
Last Answer : (d) electrons
Description : A proton and a α particle enter a region having a perpendicular uniform magnetic field. The ratio of time period of proton (τp) to time period of α particle (τα) is a) 1:4 b) 4:1 c) 2:1 d) 1:2
Last Answer : d) 1:2
Description : The radius of hydrogen atom is about a) 5 x 10-11 m b) 5 x 10-11 cm c) 5 x 10-11 mm d) 5 x 10-11 dm
Last Answer : a) 5 x 10-11 m
Description : Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero
Last Answer : (b) Nearly equal to emitter current
Description : The output waveform produced due to time base generator in a CRO is a) saw tooth b) sinusoidal c) linear d) helical
Last Answer : a) saw tooth
Description : A circuit which develops voltage across the horizontal deflection plates is known as a) Time base generator b) Electron gun c) Thermionic diode d) Zener diode
Last Answer : a) Time base generator
Description : An α particle moves perpendicular to a constant magnetic field of strength 1.2 T in a circular path of radius 0.7 m. The speed of α particle in ms-1 is ______________ a) 2.7 × 107 b) 2.6 × 107 c) 3.2 × 107 d) 2.0 × 107
Last Answer : a) 2.7 × 107
Description : The operational amplifier is _______ (a) High gain amplifier (b) high power amplifier (c)high resistance amplifier (d)low resistance amplifier
Last Answer : a) High gain amplifier
Description : An OP-AMPs can amplify _______ (a) D.C (b) A.C (c) both A.C & D.C (d) none of above
Last Answer : b) A.C
Description : Non-inverting amplifier circuits have _______ (a) Very high input impedance (b) very low input impedance (c) low output impedance (d) none of above
Last Answer : (a) Very high input impedance
Description : Process of conversion low voltage to high voltage is called _______ (a) Rectification (b)forward bias (c) reverse bias (d) amplification
Last Answer : (d) amplification
Description : _______ electric power is the most common method used by electrical grids to transfer power. (A) One-phase (B) Two-phase (C) Three-phase (D) None of the above
Last Answer : Three-phase electric power is the most common method used by electrical grids to transfer power.
Description : A galvanometer has resistance of 120 Ω. In order to pass 5% of the main current in it, the value of shunt resistance Rs must be equal to a) 6.3 Ω b) 6 Ω c) 2 Ω d) 2.3 Ω
Last Answer : a) 6.3 Ω
Description : A typical nucleus is less than _____ in diameter. a) 1010 m b) 10-10 m c) 1014 m d) 10 -14 m
Last Answer : d) 10 -14 m
Description : The value of Rydberg’s constant is a) 1.0974 x 10-7 m-1 b) 1.0974 x 107 m-1 c) 1.0974 x 107 m-2 d) 1.0974 x 10-7 m-2
Last Answer : b) 1.0974 x 107 m-1
Description : Substances of conductivity between 10–10 10–20 (n m )–1 are: a) Insulators b) Semiconductors c)Super conductors d)Good conductors
Last Answer : a) Insulators
Description : Three equal resistors connected in series with a source of e m f together dissipate 10 W of power each. What will be the power dissipated if the same resistors are connected in parallel across the same source of e m f? a. 40 W b. 90W c. 100W d. 120W
Last Answer : b. 90W
Description : CAT Scanners can detect density differences of the order of a) 50 percent b) 10 percent c) 1 percent d) 40 percent
Last Answer : c) 1 percent
Description : Relativistic velocity is of the order of, a) 15 1 of the velocity of light b) 20 1 of the velocity of light c) 10 1 of the velocity of light d) All the above
Last Answer : d) All the above
Description : Good conductors have conductivity of the order of a) 10–10 (m)–1 b) 10–7 (m)–1 c) 10 7 (m)–1 d) 10–9 (m)–1
Last Answer : c) 10 7 (m)–1
Description : A galvanometer of 65 Ω resistance gives full scale deflection with 4 mA current. In order to convert it into ammeter, the range of 10 A is connected with it, the shunt resistance should be a) 0.1 Ω b) 0.2 Ω c) 0.06 Ω d) 0.03 Ω
Last Answer : d) 0.03 Ω
Description : Which of the following actions can be carried out in order to prevent thermal runaway in a transistor? A. Increase the current through the collector-base junction. B. Install a heat sink. ... point to increase collector current. D. Increase the potential difference between the emitter and the base.
Last Answer : Answer: B
Description : The minimum charge on any electron be less than: (a) 1.6×10−19C (b) 3.2×10−19C (c) 1.8×10−19C (d) 9.1×10−19C
Last Answer : (a) 1.6×10−19C
Description : In the phenomenon of Laser production, atom can reside in the meta stable state for a) ~ 10-3 s b) ~ 10-8 s c) ~ 10-4 s d) ~ 10-10 s
Last Answer : a) ~ 10-3 s