Description : The S.I. unit of Rydberg’s constant is a) m-2 b) m-1 c) cm-1 d) cm-2
Last Answer : b) m-1
Description : The product of uncertainties of two physical observables must be approximately equal to a)Coulomb’s constant K b) Rydberg’s constant R c)Planck’s constant d)All of the above
Last Answer : c)Planck’s constant
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 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 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 : 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 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 : 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 : 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 : A 2 kg block is dropped from a height of 4 metre onto a spring of force constant k = 1960 N/m. The spring will be compressed through a.1 cm b.4.5 cm c.3 cm d.8 cm e.107 dynes
Last Answer : d. 8 cm
Description : The claddingwhichsurroundsthe fiber core a. is used to reduce optical interference b. is used to protect the fiber c. acts to help guide the light in the core d. ensures that the refractive index remains constant
Last Answer : c. acts to help guide the light in the core
Description : Electromagneticwaves are refractedwhen they a. pass into a medium of different dielectric constant b. are polarized at right angles to the direction of propagation c. encounter a perfectly conducting plane d. pass through a small slot in a conducting plane
Last Answer : a. pass into a medium of different dielectric constant
Description : Thevelocityfactor of a transmissionline a. depends on the dielectric constant of the material used b. increases the velocity along the transmission line c. is govern by the skin effect d. is higher for a solid dielectric than for air
Last Answer : a. depends on the dielectric constant of the material used
Description : Even though the main engine runs at varying speeds, how does the alternator maintain constant frequency?
Last Answer : By use of thyristor controlled frequency (rpm) converters.
Description : Dimension of Rydberg constant is a) LT-1 b) L-1 c) (LT)-1 d) L-1T
Last Answer : b) L-1
Description : The SI unit of Planck’s constant is a) Joule – Sec-1 b) Joule – Sec-2 c) Joule – Sec d) Joule – Sec2
Last Answer : c) Joule – Sec
Description : With increase in the velocity of an object its mass will a) Increase b) Decrease c) Remain constant d) None of the above
Last Answer : a) Increase
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 : If the motor is overloaded, then the magnitude of ‘back emf’” a. Increases b. Decreases c. Constant d. Becomes zero
Last Answer : Increases
Description : The induced emf is produced in a circuit due to: a. Initial magnetic flux b. final magnetic flux c. Change of magnetic flux d. constant magnetic flux
Last Answer : d. constant magnetic flux
Description : When the field is strong, the lines of force are: (a) Closer (b) Parallel (c) Farther (d) All of above 45. The electric lines of force determine the strength of an: (a) Gravitational field (b) Constant field (c) Magnetic field (d) Electric field
Last Answer : d) Electric field
Description : A 2 m long shaft rotates about one end at 20 rad/s. It begins to accelerate with ? = 10 rads/s2. After how long, in seconds, will the velocity of the free end reach 100 m/s? a.3 b.107 dynes c.5 d.6 e.7
Last Answer : a. 3
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 : 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 : 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 : 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 unit of relative permeability is (a) henry/metre (b) henry (c) henry/sq. m (d) it is dimensionless
Last Answer : (d) it is dimensionless
Description : The left hand rule correlates to (a) current, induced e.m.f. and direction of force on a conductor (b) magnetic field, electric field and direction of force on a conductor (c) self induction, ... and direction of force on a conductor (d) current, magnetic field and direction of force on a conductor
Last Answer : (d) current, magnetic field and direction of force on a conductor
Description : If electron has to be confined in the nucleus, its speed would have to be greater than a) 1010 cm/s b) 1010 m/s c) 1020 m/s d) 1020 cm/s
Last Answer : b) 1010 m/s
Description : The presence of anti-matter was predicted by a) P.A.M Dirac b) Anderson c) Einstein d) Chamberlain
Last Answer : a) P.A.M Dirac
Description : A semiconductor formed by addition of trivalent impurity is : a) P–Type b) N–Type c) Q–type d) M–Type
Last Answer : d) M–Type
Description : The dimension of strain is a) [L] b) [ML2T –2 ] c) [M L–1 T –2 ] d) Dimensionless
Last Answer : d) Dimensionless
Description : S.I unit of strain is a) Newton b) N m–2 c) Pascal d) no unit
Last Answer : a) Newton
Description : S.I unit of stress is: a) N/m b) N m c) Nm–2 d) Newton
Last Answer : c) Nm–2
Description : One tesla equals a) 1 NA-1m -1 b) 1 NA-2m -3 c) 1NAm-1 d) 1NA-1 m
Last Answer : a) 1 NA-1m -1
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 : SI unit of resistivity is a. ohm b. Ohm×m c. Ohm×m-1 d. Ohm×m2
Last Answer : c. Ohm×m-1
Description : Internal resistance is the resistance offered by a. source of e m f b. Conductor c. Resistor d. Capacitor
Last Answer : a. source of e m f
Description : The SI units of permitivity are: (a) N.m/C2(b) C2/N.m2 (c) N.m2/C2(d) N.m/C
Last Answer : (b) C2/N.m2
Description : The breaking strength of a rope is 400 N. A fireman weighing 60 kg slides down the rope. The rope will break if a.107 dynes b.the acceleration is 7.5 m/s2 c.the acceleration is 1.2 m/s2 d.the acceleration is 3.1 m/s2 e.the slides with an acceleration of 15 m/s2
Last Answer : c. the acceleration is 1.2 m/s2
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 : Please ripley me due to emergency
Last Answer : To calculate the flux density in the ring, you need to use the following formula: B = (μ * I * N) / (2 * π * r) where: B is the flux density in the ring (in teslas) μ is the relative permeability ... 2 * π * 0.127 m) = 0.53 T So the flux density in the ring would be approximately 0.53 teslas.
Description : What is the best value possible?
Last Answer : 1 is the best value possible. That is possible with a purely resistive load.
Description : What is the usual value you see onboard?
Last Answer : Ask E/O, usually 0.8.
Description : The value of first quantized Bohr orbit radius of hydrogen atom is a) 0.0053 nm b) 5.3 nm c) 0.053 nm d) 0.053 cm
Last Answer : c) 0.053 nm
Description : The minimum frequency required to eject electrons from a metallic surface is called a) Critical frequency b) Peak value of frequency c) Threshold frequency d)Photo frequency
Last Answer : c) Threshold frequency
Description : On increasing the reverse bias to a large value in a p-n junction diode current (a) Increases slowly (b) Remains fixed (c) Suddenly increases (d) Decreases slowly
Last Answer : (c) Suddenly increases
Description : In a half wave rectifier the rms value of AC component of the waves (a) Zero (b) Equal to DC value (c) More than DC value (d) Less than DC value
Last Answer : b) Equal to DC value