12th Class Physics MCQ Test With Answer for Physics Full Book

Out of the following which material is brittle.

• Wrought iron A
• Copper B
• Tungsten C
• High steel carbon D

Iodine -131 is used for the treatment by

• Bones A
• Eyes B
• thyroid glands C
• Lungs D

When a PN-Junction is reverse biased the depletion region is.

• Widened A
• Narrowed B
• Normal C
• None of these D

• Lenz's law A
• Faraday's law B
• Ampere's law C
• None of these D

A voltmeter is always connected in

• Parallel A
• Series B
• Perpendicular C
• Straight line D

The first spectral lines were discovered in 1885, were

• Paschen series A
• Balmer series  B
• Pfund series C
• Bracket series D

In RLC series circuit at resonance the phase difference between capacitor and inductor reactance is.

• 90^o A
• 270^o B
• 0^o C
• 180^o D

The fact that electric field exist in space around an electrical charge is

• Electrical property A
• Gravitational property B
• Intrinsic property of nature C
• Extrinsic property of nature D

One use of a single p-n junction semiconductor in an electrical circuit is a

• Rectifier A
• Transistor B
• Battery C
• Diode D

The maximum kinetic energy of emitted photo electrons depends upon.

• The intensity of incident light A
• Frequency of the incident light B
• Metal surface C
• Both frequency of incident light and metal surface. D

Binding energy per nucleus for uranium is above:

• 6.7 Mev A
• 7.7 Mev B
• 6.9 MeV C
• 7.9 MeV D

The reactance is the ratio of

• V_rms/I_rms A
• V_rms x I_rms B
• I_rms/V_rms C
• V_max x V_rms D

Energy density of an inductor is:

• UM=1/2μ_∘/B² A
• Um = 2μ_∘/B B
• UM = 1/2B²/μ_∘ C
• Um = 2B²/μ_∘ D

If magnetic field is doubled then magnetic energy density becomes.

• Four times A
• Two times B
• Three times C
• Six times D

Conductors have conductivities of order:

• 10³(Ωm)-1 A
• 10⁷(Ωm)^-1 B
• 10⁷Ωm^-1 C
• 10^-6Ω D

One weber is equal to:

• N.A ²/m A
• N.m²/A B
• N.A/m C
• N.m/A D

The numerical value of Compton wavelength is equal to

• 3.43 x 10^-12 m A
• 1.43 x 10^-12m B
• 2.43 x 10^-12m C
• 0.43 x 10^-12m D