Q. What is the primary use of sodium bicarbonate in households?
A.
Cleaning agent
B.
Food preservative
C.
Antacid
D.
All of the above
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Solution
Sodium bicarbonate is used for cleaning, as a food preservative, and as an antacid.
Correct Answer: D — All of the above
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Q. What is the primary use of sodium bicarbonate?
A.
Baking
B.
Medicine
C.
Cleaning
D.
All of the above
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Solution
Sodium bicarbonate is used in baking, medicine, and cleaning.
Correct Answer: D — All of the above
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Q. What is the primary use of Teflon?
A.
Insulation
B.
Non-stick coatings
C.
Adhesives
D.
Textiles
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Solution
Teflon is primarily used for non-stick coatings in cookware due to its low friction properties.
Correct Answer: B — Non-stick coatings
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Q. What is the principal quantum number for an electron in the 4th shell?
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Solution
The principal quantum number (n) corresponds to the shell number. For the 4th shell, n=4.
Correct Answer: D — 4
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Q. What is the principal quantum number for an electron in the 5d subshell?
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Solution
The principal quantum number n for the 5d subshell is 5.
Correct Answer: C — 5
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Q. What is the principal quantum number for an electron in the ground state of a hydrogen atom?
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Solution
The ground state of a hydrogen atom corresponds to n=1.
Correct Answer: B — 1
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Q. What is the principal quantum number of an electron in the 3p orbital?
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Solution
The principal quantum number (n) indicates the energy level of an electron. For a 3p orbital, n = 3.
Correct Answer: C — 3
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Q. What is the principal quantum number of an electron in the 4s orbital?
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Solution
The principal quantum number (n) indicates the energy level of an electron. For the 4s orbital, n = 4.
Correct Answer: C — 4
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Q. What is the principal quantum number of the outermost electron in chlorine?
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Solution
Chlorine has an atomic number of 17, and its outermost electrons are in the n=3 shell.
Correct Answer: B — 3
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Q. What is the principal quantum number of the outermost electron in potassium (K)?
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Solution
Potassium has the electronic configuration [Ar] 4s1, so the principal quantum number of the outermost electron is 4.
Correct Answer: A — 3
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Q. What is the principal quantum number of the valence electrons in chlorine?
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Solution
Chlorine has an atomic number of 17, and its valence electrons are in the n=3 shell.
Correct Answer: B — 3
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Q. What is the principal value of cot^(-1)(0)?
A.
0
B.
π/2
C.
π
D.
undefined
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Solution
cot^(-1)(0) = π/2
Correct Answer: B — π/2
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Q. What is the principal value of sec^(-1)(2)?
A.
π/3
B.
π/4
C.
π/6
D.
0
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Solution
sec^(-1)(2) = π/3, since sec(π/3) = 2.
Correct Answer: A — π/3
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Q. What is the principle behind a lever?
A.
Conservation of momentum
B.
Mechanical advantage
C.
Conservation of energy
D.
Centripetal force
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Solution
The principle behind a lever is mechanical advantage, which allows a smaller force to lift a larger load.
Correct Answer: B — Mechanical advantage
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Q. What is the principle behind a potentiometer?
A.
It measures current in a circuit
B.
It measures voltage by balancing it against a known voltage
C.
It measures resistance directly
D.
It measures power in a circuit
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Solution
A potentiometer measures voltage by balancing it against a known voltage, allowing for accurate voltage measurements without drawing current from the circuit.
Correct Answer: B — It measures voltage by balancing it against a known voltage
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Q. What is the principle behind a thermometer?
A.
Expansion of liquid with temperature
B.
Contraction of gas with temperature
C.
Change in color with temperature
D.
Change in pressure with temperature
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Solution
Thermometers work on the principle of expansion of liquid (like mercury) with temperature.
Correct Answer: A — Expansion of liquid with temperature
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Q. What is the principle behind Archimedes' principle?
A.
Buoyant force
B.
Pressure difference
C.
Surface tension
D.
Viscosity
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Solution
Archimedes' principle states that a body submerged in a fluid experiences a buoyant force equal to the weight of the fluid displaced.
Correct Answer: A — Buoyant force
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Q. What is the principle behind electromagnetic induction?
A.
Magnetic fields can create electric fields
B.
Electric fields can create magnetic fields
C.
Both A and B
D.
None of the above
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Solution
Electromagnetic induction is based on the principle that a changing magnetic field can induce an electric field and vice versa.
Correct Answer: C — Both A and B
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Q. What is the principle behind nuclear fission?
A.
Splitting of heavy nuclei
B.
Combining of light nuclei
C.
Emission of photons
D.
Absorption of neutrons
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Solution
Nuclear fission is the process where a heavy nucleus splits into two or more lighter nuclei, releasing energy.
Correct Answer: A — Splitting of heavy nuclei
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Q. What is the principle behind sonar technology?
A.
Reflection of sound waves
B.
Refraction of sound waves
C.
Diffraction of sound waves
D.
Interference of sound waves
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Solution
Sonar technology is based on the reflection of sound waves to detect objects underwater.
Correct Answer: A — Reflection of sound waves
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Q. What is the principle behind the Doppler effect?
A.
Change in frequency due to relative motion
B.
Change in amplitude due to distance
C.
Change in speed due to medium
D.
Change in wavelength due to temperature
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Solution
The Doppler effect is the change in frequency (and wavelength) of a wave in relation to an observer moving relative to the wave source.
Correct Answer: A — Change in frequency due to relative motion
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Q. What is the principle behind the law of conservation of mass?
A.
Mass can be created
B.
Mass can be destroyed
C.
Mass is constant in chemical reactions
D.
Mass is variable in reactions
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Solution
The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.
Correct Answer: C — Mass is constant in chemical reactions
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Q. What is the principle behind the operation of a laser?
A.
Spontaneous emission
B.
Stimulated emission
C.
Absorption
D.
Reflection
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Solution
Lasers operate on the principle of stimulated emission, where an incoming photon stimulates an excited electron to emit a photon of the same energy, phase, and direction.
Correct Answer: B — Stimulated emission
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Q. What is the principle behind the operation of a polarimeter?
A.
Measuring the speed of light
B.
Determining the wavelength of light
C.
Measuring the rotation of polarized light
D.
Calculating the intensity of light
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Solution
A polarimeter measures the angle of rotation of polarized light as it passes through a sample, which can indicate the concentration of optically active substances.
Correct Answer: C — Measuring the rotation of polarized light
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Q. What is the principle behind the operation of a transformer?
A.
Conservation of energy
B.
Electromagnetic induction
C.
Thermal expansion
D.
Mechanical advantage
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Solution
Transformers operate on the principle of electromagnetic induction, where a changing magnetic field induces an electromotive force (EMF) in a coil.
Correct Answer: B — Electromagnetic induction
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Q. What is the principle behind the operation of an electric generator?
A.
Electromagnetic induction
B.
Thermal expansion
C.
Photoelectric effect
D.
Chemical reaction
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Solution
Electric generators operate on the principle of electromagnetic induction, converting mechanical energy into electrical energy.
Correct Answer: A — Electromagnetic induction
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Q. What is the principle behind the operation of an electric motor?
A.
Electromagnetic induction
B.
Lorentz force
C.
Magnetic resonance
D.
Thermal expansion
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Solution
Electric motors operate on the principle of the Lorentz force, where a current-carrying conductor in a magnetic field experiences a force that causes it to rotate.
Correct Answer: B — Lorentz force
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Q. What is the principle behind the working of a 3D movie glasses?
A.
Color filtering
B.
Polarization
C.
Refraction
D.
Diffraction
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Solution
3D movie glasses use polarization to filter different images for each eye, creating a three-dimensional effect.
Correct Answer: B — Polarization
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Q. What is the principle behind the working of a hydraulic lift?
A.
Bernoulli's principle
B.
Archimedes' principle
C.
Pascal's law
D.
Newton's law
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Solution
A hydraulic lift works on Pascal's law, which states that pressure applied to a confined fluid is transmitted undiminished in all directions.
Correct Answer: C — Pascal's law
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Q. What is the principle behind the working of a sonar?
A.
Reflection of sound waves
B.
Refraction of sound waves
C.
Diffraction of sound waves
D.
Interference of sound waves
Show solution
Solution
Sonar works on the principle of reflection of sound waves to detect objects underwater.
Correct Answer: A — Reflection of sound waves
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