Coercive force opposes which process?
Correct answer C. Demagnetisation
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Physics MCQs
Page 32 of Physics multiple-choice questions with answers. Tap an option to check yourself.
Page 32 of 45
What happens at the Curie temperature?
Correct answer C. Ferromagnetic materials become paramagnetic
What is any change in the shape, length or volume of a body caused by an external force called?
Correct answer A. Deformation
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What are materials called that undergo plastic deformation before they break?
Correct answer A. Ductile
A uniform steel wire 4 m long with a cross-sectional area of 3 × 10⁻⁶ m² is stretched by 1 mm. If Young’s modulus of steel is 2 × 10¹¹ N m⁻², how much energy is stored in the wire?
Correct answer B. 0.075 J
A rubber cord 1 m long has a cross-sectional area of 2 cm². A tensile force of 10 N stretches it by 1 cm. What is the Young’s modulus of the rubber?
Correct answer A. 5 × 10⁶ N m⁻²
What is the SI unit of the modulus of elasticity?
Correct answer D. N m⁻²
What represents the energy needed to magnetise and demagnetise a material?
Correct answer B. Hysteresis loop area
Which device is used to detect extremely weak magnetic fields?
Correct answer B. SQUIDs
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According to the band theory of solids, what kind of band structure does a semiconductor have?
Correct answer D. A completely filled valence band, a partially filled conduction band and a narrow forbidden band
How does the electrical conductivity of an intrinsic semiconductor change as temperature rises?
Correct answer A. Increases
Which of these has the largest energy gap between its valence and conduction bands?
Correct answer C. Non-metals
What is a band that is completely filled with electrons called?
Correct answer A. Core band
The band theory of solids satisfactorily explains the nature of which materials?
Correct answer D. All of the above
What is it called when the density of atoms in a crystal is the same along any direction?
Correct answer D. Homogeneity
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The angles between the faces stay the same in every sample of a given crystal. What is this property called?
Correct answer C. The external symmetry of form
What are materials called whose valence electrons are tightly bound to their atoms at low temperature?
Correct answer B. Insulators
Under which condition does a ferromagnetic material become fully magnetised?
Correct answer B. Alternating current at its peak value
What name is given to the energy band occupied by the valence electrons?
Correct answer A. Valence band
What is the process of joining small molecules to form a large molecule called?
Correct answer A. Polymerisation