Total Number of Question/s - 5154

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  • 1. Electric Charges and Fields - Quiz


    SAMPLE QUESTIONS


    1. Five balls numbered 1,2,3,4, and 5 are suspended using separate threads. The balls (1,2), (2,4) and (4,1) show electrostatic attraction, while balls (2,3) and (4,5) show repulsion. Therefore, ball 1 must be
    a) negatively charged
    b) Positively charged
    c) neutral
    d) made of metal

    2. A parallel plate capacitor of capacitance 10μF is connected across a battery of emf 5 mV. Now, the space between the plates of the capacitor is filled with a dielectric material of dielectric constant K = 5. then, the charge that will flow through the battery till equilibrium is reached is
    a) 250μC
    b) 250 nC
    c) 200 nC
    d) 200 μC

  • 2. Electrostatic Potential and Capacitance - Quiz


    SAMPLE QUESTIONS


    1. Charge -q,Q, and -q are placed at an equal distance on a straight line. If the total potential of the system of three charges is zero, then find the ratio Q/q.

    a) 1/2
    b) 1/4
    c) 2/3
    d) 3/4

    2. Two condensers of capacities C1 and C2 are connected in parallel, they will have capacitance
    a) C1 / C2
    b) C2 / C1
    c) C1 + C2
    d) C1 - C2

  • 3. Current Electricity - Quiz


    SAMPLE QUESTIONS


    1. Equivalent resistance across AB in the following network will be

    a) 1 Ω
    b) 2 Ω
    c) 3 Ω
    d) 4 Ω

    2. An unknown resistance R1 is connected in series with a resistance of 10 Ω. This combination is connected to one gap of a metre bridge while, a resistance R2 is connected in the other gap. The balance point is at 50 cm. Now, when the 10Ω resistance is removed the balance point shifts to 40 cm. The value of R1 is (in ohm)
    a) 20
    b) 10
    c) 60
    d) 40

  • 4. Moving Charges and Magnetism - Quiz


    SAMPLE QUESTIONS


    1. In the given figure, the electron enters into the magnetic field. It deflects in

    a) + ve X direction
    b) - ve C direction
    c) + ve Y direction
    d) - ve Y direction

    2. From a cylinder of radius R, a cylinder of radius R/2 is removed, as shown in figure. Current flowing in the remaining cylinder is I. Then, magnetic field strength is

    a) zero at point A
    b) zero at point B
    c) $\frac{\mu _{0}I}{2\pi R}$ at point A
    d) $\frac{\mu _{0}I}{3\pi R}$ at point B

  • 5. Magnetism and Matter - Quiz


    SAMPLE QUESTIONS


    1. A bar magnet is oscillating in the earth`s magnetic field with time period T. If its mass in increased four times then its time period will be
    a) 4 T
    b) 2 T
    c) 3 T
    d) T

    2. The intensity of magnetic field due to an isolated pole of strength m at a point at distant r from it will be
    a) m/r2
    b) mr2
    c) r2/m
    d) m/r

  • 6. Electromagnetic Induction - Quiz


    SAMPLE QUESTIONS


    1. A copper rod is bent into a semi-circle of radius a and at ends straight parts are bent along diameter of the semi-circle and are passed through fixed, smooth and conducting ring O and O' as shown in figure. A capacitor having capacitance C is connected to the rings. The system is located in a uniform magnetic field of induction B such that axis of rotation OO' is perpendicular to the field direction. At initial moment of time (t = 0), plane of semi-circle was normal to the field direction and the semi-circle is set in rotation with constant angular velocity ω. Neglect the resistance and inductance of the circuit. The current flowing through the circuit as function of time is

    a) $\frac{1}{4}\pi \omega ^{2}a^{2}CB\, cos\omega t$
    b) $\frac{1}{2}\pi \omega ^{2}a^{2}CB\, cos\omega t$
    c) $\frac{1}{4}\pi \omega^{2}a^{2}CB, sin\omega t$
    d) $\frac{1}{2}\pi \omega ^{2}a^{2}CB\, sin\omega t$

    2. The energy stored in an inductor is
    a) Electrostatic
    b) Electromagnetic
    c) Magnetic
    d) Mechanical

  • 7. Alternating Current - Quiz


    SAMPLE QUESTIONS


    1. The rms value of an ac of 50 Hz is 10 A. The time taken by an alternating current in reaching from zero to maximum value and the peak value will be
    a) 2 × 10-2 s and 14.14 A
    b) 1 × 10-2 s and 7.07 A
    c) 5 × 10-3 s and 7.07 A
    d) 5 × 10-3 s and 14.14 A

    2. A 50Hz A.C. source of 20 volts is connected across R and C as shown in (figure) below. The voltage across R is volts. The voltage across C is

    a) 8 V
    b) 16 V
    c) 10 V
    d) Not possible to determine unless values of R and C are given

  • 8. Electromagnetic Waves - Quiz


    SAMPLE QUESTIONS


    1. Which of the following are not electromagnetic waves?
    a) Cosmic rays
    b) Gamma rays
    c) β - rays
    d) X - rays

    2. If λv, λx and λm respectively, the wavelengths of visible light, X-rays and microwaves respectively, then
    a) λm > λx > λv
    b) λv > λm > λx
    c) λm > λv > λx
    d) λv > λx > λm

  • 9. Ray Optics and Optical Instruments - Quiz


    SAMPLE QUESTIONS


    1. An object 15 cm high is placed 10cm from the optical center of an thin lens. Its image is formed 25cm from the optical center on the same side of the lens as the object. The height of the image is
    a) 25.5 cm
    b) 0.2 cm
    c) 16.7 cm
    d) 37.5 cm

    2. A diver in a swimming pool wants to signal his distress to a person standing on the edge to the pool by flashing his water proof flash light
    a) He must direct the beam vertically upward
    b) He has to direct the beam horizontal
    c) He has to direct the beam at an angle to the vertical which is slightly less than the critical angle of incidence for total internal reflection
    d) He has to direct the beam at an angle to the vertical which is slightly more than the critical angle of incidence for the total internal reflection.

  • 10. Wave Optics - Quiz


    SAMPLE QUESTIONS


    1. The slits in a double-slit interference experiment are illuminated by orange light ( λ = 60 nm ). A thin transparent plastic of thickness t is placed in front of one of the slits . The number of fringes shifting on screen is plotted versus the refractive index μ of the plastic in graph shown in figure. The value of t is

    a) 4.8 mm
    b) 640 μm
    c) 24μm
    d) none of these

    2. Two periodic waves of intensities I1 and I2 pass through a region at the same time in the direction. The sum of the maximum and minimum intensities is
    a) 2(I1 + I2)
    b) I1 + I2
    c) (√I1 + √2)2
    d) (√I1 - √I2)2

  • 11. Dual Nature of Radiation and Matter - Quiz


    SAMPLE QUESTIONS


    1. The maximum velocity of electrons emitted from a metal surface is v. What would be the maximum velocity if the frequency of incident light is increased by a factor of 4?
    a) 2v
    b) > 2v
    c) < 2v
    d) between 2v and 4v

    2. In a photoelectric cell, the wavelength of incident light is changed from 4000 Å to m 3600 Å. The change in stopping potential will be
    a) 0.14 V
    b) 0.24 V
    c) 0.35 V
    d) 0.44 V

  • 12. Nuclei - Quiz


    SAMPLE QUESTIONS


    1. Match the following
    List I List II
    A. Gravitons 1. Hyperons
    B. Baryons 2. Positrons
    C. Pions 3. Particles with zero mass and with a spin of half units
    D. Leptons 4. Decay to μ-mesons
    5. Massless particles with a probable spin of two units
    a) A-E, B-H, C-G, D-I
    b) A-I, B-E, C-H, D-G
    c) A-H, B-F, C-I, D-E
    d) A-F, B-G, C-E, D-H

    2. In radioactive decay process, the negatively charged emitted -particles are
    a) The electrons present inside the nucleus
    b) The electron produced as a result of the decay of neutrons inside the nucleus
    c) The electrons produced as a result of collisions between atoms
    d) The electrons orbiting around the nucleus

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


    SAMPLE QUESTIONS


    1. The given truth table is of
     

    a) OR gate
    b) AND gate
    c) NOT gate
    d) XOR gate

    2. The valence band and conduction band of a solid overlap at low temperature, the solid may be
    a) A metal
    b) A semiconductor
    c) An insulator
    d) None of these

  • 14. Communication Systems - Quiz


    SAMPLE QUESTIONS


    1. In a detector, output circuit of R = 10 Kw and C = 100 μF , The frequency of carrier signal it cab detect is
    a) > > 1 MH z
    b) 0.1 kHz
    c) > > 1GHz
    d) 103 Hz

    2. An antenna is of height 500 m. What will be its range (Radius of the earth is 6400 km)?
    a) 800 km
    b) 100 km
    c) 50 km
    d) 80 km

  • 15. Atoms - Quiz


    SAMPLE QUESTIONS


    1. An electron in H atom makes a transition from n = 3 to n = 1. The recoil momentum of H atom will be
    a) $6.45 \times 10^{-27}N s$
    b) $6.45 \times 10^{-24}N s$
    c) $6.8 \times 10^{-27}N s$
    d) $6.8 \times 10^{-24}N s$

    2. The wavelength of light emitted in the visible region by He+ ions after collisions with H atoms is
    a) 6.5 x 10-7 m
    b) 5.6 x 10-7 m
    c) 4.8 x 10-7 m
    d) 4.0 x 10-7 m

  • 16. Electric flux and Gauss Law - Quiz


    SAMPLE QUESTIONS


    1. A spherical shell of radius R = 1.5 cm has a charge q = 20μC uniformly distributed over it. The force exerted by one half over the other half is
    a) zero
    b) 10-2N
    c) 500 N
    d) 2000 N

    2. If the flux of the electric field through a closed surface is zero, then
    a) the electric field must be zero everywhere on the surface
    b) the total charge inside the surface must be zero
    c) the electric field must be uniform throughout the closed surface
    d) the charge outside the surface must be zero

  • 17. Electrical Measuring Instrument - Quiz


    SAMPLE QUESTIONS


    1. A potentimeter is connected across A and B and a balance is obtained at 64.0 cm. When the potentimeter lead at B is moved to C, a balance is found at 8.0 cm. If the potentimeter is now connected across B and C, a balance will be found at

    a) 8.0 cm
    b) 56. cm
    c) 64. cm
    d) 72.0 cm

    2. In the shown arrangement of a meter bridge, if AC corresponding to nulll deflection of galvanometer is x, what would be its value if the radius of the wire AB is doubled?

    a) x
    b) x/4
    c) 4x
    d) 2x

  • 18. Heating Effect of Current - Quiz


    SAMPLE QUESTIONS


    1. An electric kettle (rated accurately at 2.5 kW) is used to heat 3kg of water from 150C to boiling point . It takes 9.5 min. Then the amount of heat that has been lost is
    a) 3.5 x 105 J
    b) 7 x 108J
    c) 3.5 x 104 J
    d) 7 x 108 J

    2. An electric bulb rated for 500W at 100V is used in a circuit having a 200V supply. The resistance R that must be put in series with the bulb, so that the bulb draws 500W, is
    a) 18Ω
    b) 20Ω
    c) 40Ω
    d) 700Ω