Study HubHubPage 34/118Scan verified MCQs with the answer highlighted, then open explanations when you want the reasoning.
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Units And Measurement
Length, mass, time, intensity of light, and amount of substance are examples of ___________?
Length, mass, time, intensity of light, and amount of substance are fundamental physical quantities that are defined independently and serve as the basis for other measurements; hence, they are called base quantities.
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Work And Energy
An elevator weighing 3.5 x 10^-6 N is raised to a height of 1000 m in the absence of friction. The work done is _________?
Work done is calculated as force multiplied by distance. Given the elevator's weight (force) is 3.5 × 10⁻⁶ N and it is raised to a height of 1000 m, the work done is: Work = Force × Distance = 3.5 × 10⁻⁶ N × 1000 m = 3.5 × 10⁻³ J. This matches option A. The originally given correct answer (B) is incorrect based on the provided values. The weight value is very small for an elevator, but the calculation is straightforward and correct as per the question's data.
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Waves And Oscillations
Frequency is the inverse of __________?
Frequency is defined as the number of occurrences of a repeating event per unit time, and it is the inverse of the time period, which is the duration of one cycle of the event.
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Wave Optics
Two coherent sources of light produce destructive interference when the phase difference between them is ___________.
Destructive interference occurs when the phase difference between two coherent light sources is an odd multiple of π, with the simplest case being π. This causes the waves to be out of phase and cancel each other out.
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Units And Measurements
The unit of power is___________?
Power is defined as the rate of doing work or the rate of energy transfer, and its SI unit is the watt (W). Joule is a unit of energy, Newton is a unit of force, and Pascal is a unit of pressure.
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Vectors
What is the angle between the rectangular components of a vector?
The rectangular components of a vector are its projections along two perpendicular axes, typically the x and y axes. Therefore, the angle between these components is always 90° (a right angle).
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Atomic Structure
Neutron was discovered by: __________?
James Chadwick discovered the neutron in 1932, which was a significant advancement in understanding atomic structure. The other scientists listed are known for different contributions: Rutherford for the nuclear model, Bohr for atomic structure, and Einstein for relativity.
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Vectors
For anti-parallel vectors, the angle between them is equal to _________?
Anti-parallel vectors point in exactly opposite directions, so the angle between them is 180°.
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Inertia
We have two bodies: one is moving with a velocity of 2 m/s and the other is at rest. Which one has greater inertia?
Inertia is a property of matter that depends solely on the mass of the object, not on its velocity. Therefore, both bodies have the same inertia if their masses are equal, regardless of one being at rest and the other moving.
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Free Fall
A body is falling freely under gravity. How much distance does it fall during the interval between the 1st and 2nd seconds of its motion, taking g = 10 m/s²?
The distance fallen during the interval between the 1st and 2nd seconds can be found by calculating the distance fallen in 2 seconds minus the distance fallen in 1 second. Using s = 1/2 * g * t^2 with g=10 m/s², s(2) = 20 m and s(1) = 5 m, so the distance in the interval is 20 - 5 = 15 m.