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بصریات اور جدید طبیعیات

7 سوالات: نیٹ طبیعیات، جوابات اور وضاحت کے ساتھ۔

تمام سوالات جوابات کے ساتھ

  1. An object is placed 30 cm from a concave mirror of focal length 10 cm. Where is the image formed?

    • 1 15 cm from the mirror
    • 2 7.5 cm from the mirror
    • 3 20 cm from the mirror
    • 4 30 cm from the mirror
    جواب دیکھیں

    درست جواب: 15 cm from the mirror

    From 1/v + 1/u = 1/f: 1/v = 1/10 - 1/30 = 2/30, so v = 15 cm.

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  2. An object is 20 cm in front of a convex lens of focal length 10 cm. What is the magnification?

    • 1 -1
    • 2 +1
    • 3 -2
    • 4 +2
    جواب دیکھیں

    درست جواب: -1

    The object at 2f gives an image at 2f on the other side, which is real, inverted and the same size, so m = -1.

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  3. X-rays are produced when:

    • 1 Electrons are rapidly stopped by a metal target
    • 2 Alpha particles hit a screen
    • 3 A wire is heated slowly
    • 4 Light passes through glass
    جواب دیکھیں

    درست جواب: Electrons are rapidly stopped by a metal target

    When fast electrons decelerate in a metal target, they emit X-ray photons.

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  4. What is the approximate energy of a photon of wavelength 500 nm?

    • 1 0.5 eV
    • 2 1.24 eV
    • 3 2.48 eV
    • 4 5 eV
    جواب دیکھیں

    درست جواب: 2.48 eV

    E (in eV) is about 1240 divided by the wavelength in nm, so 1240 / 500 = 2.48 eV.

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  5. The binding energy of a nucleus is found from its mass defect using:

    • 1 E = hf
    • 2 E = mc^2
    • 3 E = 1/2 mv^2
    • 4 E = qV
    جواب دیکھیں

    درست جواب: E = mc^2

    The mass defect, multiplied by c squared, gives the binding energy.

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  6. Which of these has the highest frequency?

    • 1 Radio waves
    • 2 Microwaves
    • 3 Visible light
    • 4 Gamma rays
    جواب دیکھیں

    درست جواب: Gamma rays

    Gamma rays are at the high-frequency, short-wavelength end of the electromagnetic spectrum.

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  7. Constructive interference of two waves occurs when the path difference is:

    • 1 An odd multiple of half a wavelength
    • 2 A whole number of wavelengths
    • 3 A quarter of a wavelength
    • 4 Zero only
    جواب دیکھیں

    درست جواب: A whole number of wavelengths

    When the path difference is n times the wavelength, the waves arrive in phase and reinforce each other.

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طبیعیات کے مزید موضوعات
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حرارتی طبیعیات
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مقناطیسی میدان اور امالہ
جوہری اور مرکزی طبیعیات