Study HubHubPage 37/118Scan verified MCQs with the answer highlighted, then open explanations when you want the reasoning.
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Material Properties
Mohs scale is used to measure ___________?
The Mohs scale is a scale of mineral hardness used to measure the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. Therefore, it is used to measure hardness.
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Kinematics
Area under the curve of a velocity-time graph gives________?
The area under a velocity-time graph represents displacement because it is the integral of velocity with respect to time, which gives the change in position.
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Vectors
A unit vector is used to specify the ___________?
A unit vector has a magnitude of one and is used specifically to indicate the direction of a vector without regard to its magnitude.
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Electromagnetic Interaction
Field particle of electromagnetic interaction is ___________?
The field particle of electromagnetic interaction is the photon, which is the quantum of the electromagnetic field and mediates electromagnetic forces.
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Kinematics
If the velocity-time graph is a parabolic curve, then the body possesses ________?
A parabolic velocity-time graph indicates that the velocity changes with time in a quadratic manner, which means the acceleration is not constant but varies with time. The acceleration is the slope of the velocity-time graph, so a curved (parabolic) velocity-time graph corresponds to variable acceleration. Constant acceleration produces a straight line velocity-time graph (linear velocity change). Therefore, if the velocity-time graph is parabolic, the body possesses variable acceleration.
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Units And Measurements
What is the SI unit of acceleration?
The SI unit of acceleration is meters per second squared (m/s²), which represents the change in velocity per unit time. Option B correctly states this unit.
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Electric Circuits
If a wire has a resistance of 0.5 ohm, then its conductance is:
Conductance (G) is the reciprocal of resistance (R). Given R = 0.5 ohm, G = 1 / 0.5 = 2 siemens (S).
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Electromagnetism
An electric motor could be used as a: _________?
An electric motor can be used as a dynamo (generator) because both devices operate on the principle of electromagnetic induction; when an electric motor is driven mechanically, it generates electricity, functioning as a dynamo.
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Electric Current
A.C. and D.C. have the same _________?
Both alternating current (A.C.) and direct current (D.C.) produce the same heating effect when passing through a resistance, as the heating depends on the power dissipated (I²R), which is similar for equal RMS currents.
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Vector Addition
If vectors a and b are antiparallel to each other, then their resultant is _________?
When two vectors are antiparallel, they point in exactly opposite directions. The resultant vector is found by subtracting the smaller vector from the larger one, which corresponds to a - b if a and b are the vectors.