Total Number of Question/s - 5154

Just Exam provide question bank for Class XII standard. Currently number of question's are 5154. We provide this data in all format (word, excel, pdf, sql, latex form with images) to institutes for conducting online test/ examinations. Here we are providing some demo contents.

• 1. Electric Charges and Fields - Quiz

SAMPLE QUESTIONS

1. A electroscope is given a positive charge. Causing its foil leaves to separate. When an object is brought near the top plate of the electroscope, the foils separate even further. We conclude

a) that the object is positively charged
b) that the object is electrically neutral
c) that the object is negatively charged
d) none of these

2. An electric dipole of moment is lying along a uniform electric field . The work done in rotating the dipole by 900 is
a) p E/2
b) 2pE
c) p E
d) √2 p E

• 2. Electrostatic Potential and Capacitance - Quiz

SAMPLE QUESTIONS

1. Charges 2q, -q , and -q lie at the vertices of a triangle. The value of E and V at the centroid of the triangle will be
a) E ≠ 0 and V ≠ 0
b) E = 0 and V = 0
c) E = 0 and V = 0
d) E = 0 and V ≠ 0

2. Two condensers , one of capacity C and the other of capacity C/2, are corrected to a V-volt battery, as shown.
The work done in charging fully both the condensers is
a) (1/4)CV2
b) (1/4)CV2
c) (1/2)CV2
d) 2 CV2

• 3. Current Electricity - Quiz

SAMPLE QUESTIONS

1. Two wires of the same dimensions but, resistivities ρ1 and ρ2 are connected in series. The equivalent resistivity of the combination is
a) 2(ρ1 + ρ2)
b) √ρ1ρ2
c) (ρ12)/2
d) ρ12

2. The Kirchhoffs first law (ΣI = 0) and second law (ΣiR = Σε), where the symbols have their usual meanings, are respectively based on
a) Conservation of charge, conservation of energy
b) Conservation of charge, conservation of momentum
c) Conservation of energy, conservation of charge
d) Conservation of momentum, conservation of charge

• 4. Moving Charges and Magnetism - Quiz

SAMPLE QUESTIONS

1. An ammeter of resistance 22.8 Ω measures 1 A. How much shunt should be used so that it can be used to measure 20 A?
a) 1 Ω
b) 2 Ω
c) 1.2 Ω
d) 2.2 Ω

2. If a charged particle of charge to mass ratio (q/m) = α enters in a magnetic field of strength B at a speed v = (2αd)(B), then

a) angle subtended by the path of charged particle in magnetic field at the centre of circular path is 2 π
b) the charge will move on a circular path and then will come out from magnetic field at some distance from the point of insertion
c) the time for which particle will be in the magnetic field is $\frac{2\pi }{\alpha B}$
d) angle subtended by the path of charged particle in magnetic field at the centre of circular path is π/2

• 5. Magnetism and Matter - Quiz

SAMPLE QUESTIONS

1. A vertical circular coil of radius 0.1 m and having 10 turns carries a steady current. When the plane of the coil is normal to the magnetic meridian, a neutral point is observed at the centre of the coil. If BH = 314 x 10-4 T, the current in the coil is
a) 0.5 A
b) 0.25 A
c) 2A
d) 1A

2. Needles N1, N2 and N3 are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet when brought close to them will
a) Attract all three of them
b) Attract N1 and N2 strongle but repel N3
c) Attract N1 strobgle, N2 weakly & repel N3 weakly
d) Attract N1 strobgly, but repel N2 and N3 weakly.

• 6. Electromagnetic Induction - Quiz

SAMPLE QUESTIONS

1. The core of a transformer is laminated because
a) The weight of the transformer may be reduced.
b) Rusting of the core may be prevented.
c) Ratio of voltage in primary and secondary may be increased.
d) Energy losses due to eddy currents may be minimized.

2. Two identical conductors P and Q are placed on two frictionless rails R and S in a uniform magnetic field directed into the plane. If P is moved in the direction shown in figure with a constant speed, then rod Q

a) will be attracted towards P
b) will be repelled away from P
c) will remain stationary
d) may be repelled away or attracted towards P

• 7. Alternating Current - Quiz

SAMPLE QUESTIONS

1. A current source sends a current I = i0 cos (ωt). When connected across an unknown load, it gives a voltage output of v = v0 sin [ω t + (π/4)] across that load. Then the voltage across the current may be brought in phase with the current the through it by

a) connecting an inductor in series with the load
b) connecting a capacitor in series with the load
c) connecting an inductor in parallel with the load
d) connecting a capacitor in parallel with the load

2. A 220-V, 50 Hz ac generator is connected to an inductor and a 50 Ω resistance in series. The current in the circuit is 1.0 A. What is the pd across inductor?
a) 102.2 V
b) 186.4 V
c) 214 V
d) 170 V

• 8. Electromagnetic Waves - Quiz

SAMPLE QUESTIONS

1. According to the special theory of relativity. Which of the following has same value in all inertia frames?
a) Mass of an object
b) Length of an object
c) Velocity of sound
d) Velocity of light

2. Infrared radiation is detected by
a) Spectrometer
b) Pyrometer
c) Nanometer
d) Photometer

• 9. Ray Optics and Optical Instruments - Quiz

SAMPLE QUESTIONS

1. A point object is placed in front of a thick plane mirror as shown in figure below. Find the location of final image w.r.t. object.

a) 15/2 cm
b) 15 cm
c) 40/3 cm
d) 80/3 cm

2. Refractive index of a prism is $\sqrt{7/3}$ and the angle of prism is 600. The minimum angle of incidence of a ray that will be transmitted through the prism is
a) 300
b) 450
c) 150
d) 500

• 10. Wave Optics - Quiz

SAMPLE QUESTIONS

1. In youngs double slit experiment the wavelength of light was changed from while doubling the separation between the slits. Which of the following is not true to this experiments?
a) The width of the fringes change
b) The colour of fringes change
c) The separation between successive bright fringes changes
d) The separation between successive dark fringes remains unchanged

2. As a result of interference of two coherent sources of light, energy is
a) Redistributed and the distribution changes with time
b) Decreased
c) Redistributed and the distribution does not vary with time
d) Increased

• 11. Dual Nature of Radiation and Matter - Quiz

SAMPLE QUESTIONS

1. Which of the following graphs correctly represents the variation of particle momentum with associated de broglie wavelength?
a)
b)
c)
d)

2. If particles are moving with same velocity, then maximum de-Broglie wavelength is for
a) Proton
b) α- particle
c) Neutron
d) β-particle

• 12. Nuclei - Quiz

SAMPLE QUESTIONS

1. The binding energy of an electron in the ground state of He-atom is E0 = 24.6 eV. The energy required to remove both the electrons from the atom is
a) 24.6 eV
b) 79.0 eV
c) 54.4 eV
d) none of these

2. Complete the reactions:
n +92235U → n + 56Ba144 + ... + 3n
a) 3689Kr
b) 3690Kr
c) 3691 Kr
d) 3692 Kr

• 13. Semiconductor Electronics: Materials, Devices and Simple Circuit - Quiz

SAMPLE QUESTIONS

1. Zener diode is used for-
a) Producing oscillations in an oscillator
b) Amplification
c) Stabilisation
d) Rectification

2. Application of a forward bias to p-n junction
a) Increases the number of donors on the n side
b) Increases the electric field in the depletion zone
c) Increases the potential difference across the depletion zone
d) Reduces the depletion zone

• 14. Communication Systems - Quiz

SAMPLE QUESTIONS

1. For skywave propagation of a 10MHz signal, what should be the minimum electron density in ionosphere?
a) ∼ 1.2 x 103 m-3
b) ∼ 106 m-3
c) ∼1014 m-3
d) ∼1022 m-3

2. The circuit shown below acts as

a) Tuned filter
b) Low pass filter
c) High pass filter
d) Rectifier

• 15. Atoms - Quiz

SAMPLE QUESTIONS

1. A hydrogen atom and a Li++ ion are both in the second excited state. If lH and lLI are their respective electronic angular momenta , and EH and ELI their respective energies, then
a) $l_{H} < l_{LI} \ and \ |E_{H}| > |E_{LI}|$
b) $l_{H} <= l_{LI} \ and \ |E_{H}| < |E_{LI}|$
c) $l_{H} = l_{LI} \ and \ |E_{H}| > |E_{LI}|$
d) $l_{H} < l_{LI} \ and \ |E_{H}| < |E_{LI}|$

2. When voltahe applied to an X ray tube increases from V1 = 10kV to V2 = 20V, the wavelength interval between Kα line and cut-off wavelength of continuous spectrum increase by a factor of 3. Atomic number of the metallic target is
a) 28
b) 29
c) 65
d) 66

• 16. Electric flux and Gauss Law - Quiz

SAMPLE QUESTIONS

1. A sphere of radius R carries charge such that its volume charge density is proportional to the square of the distance from the center. What is the ration of the magnitude of the electric field at a distance 2R from the center to the magnitude of the electric field at a distance of R/2 from the center?
a) 1
b) 2
c) 4
d) 8

2. A hollow metallic sphere of radius 10cm is given a charge of 3.2 × 10-9C. The electric intensity at a point 4cm from the center is
a) 9 × 10-9 NC-1
b) 299 NC-1
c) 2.88 NC-1
d) zero

• 17. Electrical Measuring Instrument - Quiz

SAMPLE QUESTIONS

1. In the circuit shown in fig., the reading of the ammeter is (assume internal resistance of the battery be to zero)

a) $\frac{40}{29}A$
b) $\frac{10}{9}A$
c) $\frac{5}{3}A$
d) 2A

2. Sensitivity of a potentiometer can be increased by
a) increasing the emf of the cell
b) increasing the length of the potentiometer
c) decreasing the length of the potentiometer
d) none of the above

• 18. Heating Effect of Current - Quiz

SAMPLE QUESTIONS

1. The three resistances of equal values are arranged in different combinations shown below. Arrange them in increasing order of power dissipation.

a) III < II < IV < I
b) II < III < IV < I
c) I < IV < III < II
d) I < III < II < IV

2. The operating  temperature of the filament of lamp is 20000C. The temperature cofficient of the material of the filament is 0.0050C-1. If the atmospheric temperature is 00C, then the current in the 100W - 200V lamp when it is switched on is nearest to
a) 2.5 A
b) 3.5 A
c) 4.5 A
d) 5.5 A

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