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 : 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 : Which of the following statement is correct: (a) Similar charges attract each other (b) Similar charges attract and repel each other (c) Similar charges repel each other (d) Similar charges neither attract nor repel 9. Metals are good conductors of electricity because they have:
Last Answer : (c) Similar charges repel each other
Description : The two conductors of a transmission line carry equal current I in opposite directions. The force on each conductor is (a) proportional to 7 (b) proportional to X (c) proportional to distance between the conductors (d) inversely proportional to I
Last Answer : (b) proportional to X
Description : The force between two long parallel conductors is inversely proportional to (a) radius of conductors (b) current in one conductor (c) product of current in two conductors (d) distance between the conductors
Last Answer : (d) distance between the conductors
Description : Asingle fiber can handle asmanyvoice channel as a. a pair of copper conductors b. a1500-pair cable c. a 500-pair cable d. a 1000-pair cable
Last Answer : b. a1500-pair cable
Description : Current carried by each of the two long parallel conductors is doubled. If their separation is also doubled , force between them is
Last Answer : Increase two fold
Description : What happens to resistance of conductors when temperature rises?
Last Answer : For conductors an increase in temperature will cause their resistance to increase.
Description : Metals are good conductors of electricity because they have: (a) Large number of bounded electrons (b) Small number of electrons (c) Large number of free electrons (d) Small number of free electrons
Last Answer : (c) Large number of free electrons
Description : The temperature at which material show super conductivity is a) Super temperature b) Critical temperature c)Kelvin temperature d)Absolute
Last Answer : d)Absolute
Description : Conductivity of semi conductor is increased by: a) Decrease of temperature b) By keeping temperature constant c) Increase of temperature d) none of above
Last Answer : d) none of above
Description : Which of the following has the lowest electrical conductivity? A) Mercury B) Silver C) Copper D) Gold
Last Answer : Which of the following has the lowest electrical conductivity? A) Mercury B) Silver C) Copper D) Gold
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 : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because - (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : (3) metals are good conductors of heat Explanation: On a chilly day, the room temperature is lower than our body temperature. Since metals have a higher coefficient of thermal conductivity than plastic, they ... from our fingers will flow to the metal cap much more quickly than to the plastic body.
Description : What are the common conductors in sequence with high conductivity?
Last Answer : a. Silver b. Silver copper alloy c. Copper (Hard down and Annealed) d. Gold e. Zinc f. Platinum g. Tin h. Aluminum i. Iron j. Brass k. Phosphorous bronze l. Nickel m. Lead n. Germanium silver o. Antimony p. Platinoid q. Mercury r. Bismuth s. Platinum iridium
Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because : (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
Last Answer : metals are good conductors of heat
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 : In transistor, the base region is of the order of _______ (a) 10-5 m (b) 10-2 m (c) 10-8 m (d) 10-6 m
Last Answer : d) 10-6 m
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 : 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 : An electrical circuit with 10 branches and 7 junctions will have
Last Answer : An electrical circuit with 10 branches and 7 junctions will have 4 loop equations.
Description : Red Laser light has a wavelength of a) 630.8 nm b) 630 cm c) 632.8 nm d) 639.9 nm
Last Answer : c) 632.8 nm
Description : According to Bohr’s theory, the fourth stationary orbit of electrons in the hydrogen atom is a) 4 (0.053 nm) b) 9 (0.053 nm) c) 16 (0.053 nm) d) 25(0.053 nm)
Last Answer : c) 16 (0.053 nm)
Description : The electric intensity at a distance of 1m from the point charge is 1μC is: (a) 9 × 109 N/C (b) 9 × 106 N/C (c) 9 × 103 N/C (d) 9 N/C
Last Answer : c) 9 × 103 N/C
Description : A metallic hallow sphere of 8cm diameter is charged with 4 × 10−8c. The potential on its surface will be: (a) 90 volts (b) 9 volts (c) 9000 volts (d) 900 volts
Last Answer : c) 9000 volts
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 : A charge of 10μC and 14.4 μC are 12 cm apart, the force between them is: (a) 9 × 105 N (b) 9 × 107 N (c) 90 N (d) 108 × 107 N
Last Answer : (c) 90 N
Description : The electrostatic force of repulsion between two electrons at 1 metre is: (a) 9 × 109 N (b) 1.44 × 10−9 N (c) 2.30 × 10−28 N (d) 1 N
Last Answer : (c) 2.30 × 10−28 N
Description : When an iron piece is placed in a magnetic field (a) the magnetic lines of force will bend away from their usual paths in order to go away from the piece (b) the magnetic lines of force will bend ... to pass through the piece (c) the magnetic field will not be affected (d) the iron piece will break
Last Answer : (b) the magnetic lines of force will bend away from their usual paths in order to pass through the piece
Description : In order to obtain spectrum from the emitted radiation, the atomic gas or vapour must be excited at a) much less than atmospheric pressure b) much high than atmospheric pressure c) atmospheric pressure d) high pressure and temperature
Last Answer : a) much less than atmospheric pressure
Description : In the reverse biased p-n junction, the current is of the order of (a) Ampere (b) Milliampere (c) Microampere (d) Nano-ampere
Last Answer : (d) Nano-ampere
Description : A solid is which atoms are in a regular order is called a) Crystalline solid b) Amorphous solid c) Polymeric solid d) Glassy solid
Last Answer : a) Crystalline solid
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 : In order to have a lower cost of electrical energy generation the load factor (1) and the diversity factor should be low (2) should be low but the diversity factor should be high (3) should be high but the diversity factor should be low (4) and the diversity factor both should be high
Last Answer : In order to have a lower cost of electrical energy generation the load factor and the diversity factor both should be high
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 : 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 : The color code of green is a. 8 b. 3 c. 5 d. 7
Last Answer : c. 5
Description : Problem on electrical power and energy 7
Last Answer : Problem on electrical power and energy 7
Description : A 0-10 mA PMMC ammeter reads 5mA in a circuit; its bottom control spring snaps out suddenly the meter will now read. a) 5mA b) 10mA c) 2.5mA d) 0
Last Answer : Ans: 0
Description : The transfer function of a system is 10/(1+s) when operating as a unity feedback system, the steady state error to a step input will be a) 0 b) 1/11 c) 10 d) Infinity
Last Answer : Ans: 1/11
Description : Loss comparisons between fusionsplices andmechanicalsplices are a. 1:10 b. 10:1 c. 20:1 d. 1:20
Last Answer : a. 1:10
Description : The termresponsivityasit appliesto a light detectorisbest described as a. the time required for the signal to go from 10 to 90 percent of maximum amplitude b.the ratio ofthediode output currentto ... of output current to output power d. the ratio of output current to input current
Last Answer : b.the ratio ofthediode output currentto opticalinputpower
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
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 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 : Rest mass of the photon is a) Infinite b) Zero c) Very small d) 1.67 10-27 Kg
Last Answer : b) Zero
Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV
Last Answer : b) 1.02 MeV
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 : Thermistor with high negative temperature coefficient are very accurate for measuring low temperature especially near is a. 10 K b. 70K c. 200K d. 35K
Last Answer : c. 200K