Q. If the entropy of a system increases, what can be inferred about the spontaneity of the process?
A.
The process is non-spontaneous
B.
The process is spontaneous
C.
The process is at equilibrium
D.
None of the above
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Solution
An increase in entropy indicates that the process is spontaneous, as per the second law of thermodynamics.
Correct Answer: B — The process is spontaneous
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Q. If the entropy of a system increases, what is the effect on Gibbs Free Energy at constant temperature?
A.
ΔG increases
B.
ΔG decreases
C.
ΔG remains constant
D.
ΔG becomes zero
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Solution
If entropy increases, ΔG decreases, making the reaction more favorable.
Correct Answer: B — ΔG decreases
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Q. If the equation 2x^2 + 3x + k = 0 has one root equal to 1, what is the value of k?
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Solution
Substituting x = 1 gives 2(1)^2 + 3(1) + k = 0 => 2 + 3 + k = 0 => k = -5.
Correct Answer: A — -1
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Q. If the equation 2x^2 + 3x + k = 0 has roots 1 and -2, what is the value of k?
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Solution
Using Vieta's formulas, k = 2*1*(-2) = -4.
Correct Answer: D — 4
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Q. If the equation 2x^2 + 3x - 5 = 0 has roots r1 and r2, what is the value of r1 + r2?
A.
-3/2
B.
3/2
C.
5/2
D.
-5/2
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Solution
Using Vieta's formulas, r1 + r2 = -b/a = -3/2.
Correct Answer: A — -3/2
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Q. If the equation of a parabola is given by y^2 = 12x, what is the value of 'p'?
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Solution
In the equation y^2 = 4px, p = 3, hence the value of 'p' is 3.
Correct Answer: B — 6
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Q. If the equation of an ellipse is 9x^2 + 16y^2 = 144, what are the lengths of the semi-major and semi-minor axes?
A.
3, 4
B.
4, 3
C.
6, 8
D.
8, 6
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Solution
Rewriting the equation in standard form gives (x^2/16) + (y^2/9) = 1, so semi-major axis a = 4 and semi-minor axis b = 3.
Correct Answer: A — 3, 4
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Q. If the equation x^2 + px + q = 0 has roots 2 and 3, what is the value of p?
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Solution
Using Vieta's formulas, p = -(2 + 3) = -5.
Correct Answer: A — -5
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Q. If the equation x^2 - 5x + k = 0 has equal roots, what is the value of k?
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Solution
For equal roots, the discriminant must be zero. Thus, (-5)^2 - 4*1*k = 0 => 25 - 4k = 0 => k = 25/4 = 6.25.
Correct Answer: A — 5
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Q. If the equilibrium constant Kc for a reaction is 10 at a certain temperature, what is the value of Kc for the reverse reaction?
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Solution
The equilibrium constant for the reverse reaction is the reciprocal of the forward reaction, so Kc' = 1/Kc = 0.1.
Correct Answer: A — 0.1
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Q. If the equilibrium constant Kc for a reaction is 10, what can be said about the position of equilibrium?
A.
Products are favored
B.
Reactants are favored
C.
Equilibrium is at the center
D.
No conclusion can be drawn
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Solution
A Kc value greater than 1 indicates that the products are favored at equilibrium.
Correct Answer: A — Products are favored
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Q. If the equilibrium constant Kc for a reaction is less than 1, what does it indicate about the equilibrium position?
A.
Products are favored
B.
Reactants are favored
C.
Equal amounts of reactants and products
D.
Reaction does not occur
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Solution
A Kc value less than 1 indicates that at equilibrium, the concentration of reactants is greater than that of products, thus reactants are favored.
Correct Answer: B — Reactants are favored
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Q. If the expansion of (x + a)^n has a term 15x^3a^2, what is the value of n?
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Solution
The term is given by C(n, 3) * a^2 * x^3. Setting C(n, 3) * a^2 = 15 gives n = 6.
Correct Answer: B — 6
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Q. If the family of curves is given by y = k/x, what type of curves does it represent?
A.
Linear
B.
Hyperbolic
C.
Circular
D.
Exponential
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Solution
The equation y = k/x represents a family of hyperbolas.
Correct Answer: B — Hyperbolic
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Q. If the first term of an arithmetic series is 5 and the common difference is 3, what is the 15th term?
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Solution
a_n = a + (n-1)d = 5 + (15-1) * 3 = 5 + 42 = 47.
Correct Answer: A — 44
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Q. If the focal length of a concave lens is -10 cm, what is the nature of the image formed when an object is placed at 15 cm?
A.
Real and inverted
B.
Virtual and erect
C.
Real and erect
D.
Virtual and inverted
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Solution
Concave lenses always produce virtual and erect images regardless of the object distance.
Correct Answer: B — Virtual and erect
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Q. If the focal length of a concave mirror is 10 cm, what is the radius of curvature?
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
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Solution
The radius of curvature (R) is twice the focal length (f). Therefore, R = 2f = 2 * 10 cm = 20 cm.
Correct Answer: B — 10 cm
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Q. If the focal length of a concave mirror is 20 cm, what is the radius of curvature?
A.
10 cm
B.
20 cm
C.
30 cm
D.
40 cm
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Solution
The radius of curvature (R) is twice the focal length (f). Therefore, R = 2f = 2 * 20 cm = 40 cm.
Correct Answer: B — 20 cm
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Q. If the focal length of a lens is -10 cm, what type of lens is it?
A.
Convex lens
B.
Concave lens
C.
Bifocal lens
D.
Cylindrical lens
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Solution
A negative focal length indicates that the lens is a concave lens.
Correct Answer: B — Concave lens
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Q. If the focal length of a lens is 20 cm, what is the power of the lens?
A.
+5 D
B.
+10 D
C.
-5 D
D.
-10 D
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Solution
Power (P) = 1/f (in meters). Here, f = 0.2 m, so P = 1/0.2 = +5 D.
Correct Answer: B — +10 D
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Q. If the focal length of a lens is 25 cm, what is the power of the lens?
A.
+2 D
B.
+4 D
C.
+5 D
D.
+10 D
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Solution
Power (P) is given by P = 1/f (in meters). Thus, P = 1/0.25 m = +4 D.
Correct Answer: C — +5 D
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Q. If the focal length of a lens is doubled, how does the power of the lens change?
A.
Doubles
B.
Halves
C.
Remains the same
D.
Quadruples
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Solution
Power is inversely proportional to focal length. If f is doubled, P = 1/f will halve.
Correct Answer: B — Halves
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Q. If the following numbers are arranged in ascending order: 3, 7, 8, 12, 14, what is the range?
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Solution
Range = Maximum - Minimum = 14 - 3 = 11
Correct Answer: A — 11
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Q. If the forward reaction is exothermic, what effect does increasing the temperature have on the equilibrium position?
A.
Shifts to the right
B.
Shifts to the left
C.
No effect
D.
Increases the rate of reaction
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Solution
According to Le Chatelier's principle, increasing the temperature of an exothermic reaction shifts the equilibrium position to the left, favoring the reactants.
Correct Answer: B — Shifts to the left
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Q. If the frequency of a simple harmonic motion is doubled, what happens to the time period?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
The time period T is inversely proportional to the frequency f. If the frequency is doubled, the time period halves.
Correct Answer: B — It halves
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Q. If the frequency of a simple harmonic oscillator is halved, what happens to the period?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
Period T = 1/f, if frequency is halved, period doubles.
Correct Answer: A — It doubles
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Q. If the frequency of a sound wave is doubled, what happens to its wavelength in a given medium?
A.
Doubles
B.
Halves
C.
Remains the same
D.
Increases by a factor of four
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Solution
Wavelength is inversely proportional to frequency; if frequency is doubled, wavelength is halved.
Correct Answer: B — Halves
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Q. If the frequency of a sound wave is doubled, what happens to its wavelength?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
Wavelength is inversely proportional to frequency; if frequency is doubled, wavelength halves.
Correct Answer: B — It halves
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Q. If the frequency of a wave is doubled, what happens to its wavelength, assuming the speed of the wave remains constant?
A.
Wavelength doubles
B.
Wavelength halves
C.
Wavelength remains the same
D.
Wavelength quadruples
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Solution
According to the wave equation v = fλ, if frequency (f) is doubled and speed (v) remains constant, the wavelength (λ) must halve.
Correct Answer: B — Wavelength halves
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Q. If the frequency of a wave is doubled, what happens to its wavelength?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
The speed of a wave is given by the product of its frequency and wavelength (v = fλ). If the frequency is doubled, the wavelength must be halved to keep the speed constant.
Correct Answer: B — It halves
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