Q. What is the final concentration when 100 mL of 1 M NaCl is diluted to 500 mL? (2021)
A.
0.2 M
B.
0.5 M
C.
1 M
D.
2 M
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Solution
Using M1V1 = M2V2, (1 M)(0.1 L) = M2(0.5 L). M2 = 0.2 M.
Correct Answer: B — 0.5 M
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Q. What is the final temperature when 200 g of ice at 0°C is added to 100 g of water at 80°C? (Specific heat of water = 4.2 J/g°C) (2020)
A.
0°C
B.
20°C
C.
40°C
D.
80°C
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Solution
Using the principle of conservation of energy, the heat lost by water equals the heat gained by ice. Solving gives a final temperature of 20°C.
Correct Answer: B — 20°C
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Q. What is the final temperature when 200 g of ice at 0°C is added to 100 g of water at 80°C? (Assume no heat loss to the surroundings) (2023)
A.
0°C
B.
20°C
C.
40°C
D.
80°C
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Solution
Using heat balance: m_ice * L_f + m_water * c * (T_final - 80) = 0. Solving gives T_final = 20°C.
Correct Answer: B — 20°C
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Q. What is the final temperature when 200 g of water at 90°C is mixed with 300 g of water at 30°C?
A.
50°C
B.
60°C
C.
70°C
D.
80°C
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Solution
Using the formula m1*T1 + m2*T2 = (m1 + m2)*Tf, we find Tf = (200*90 + 300*30) / (200 + 300) = 70°C.
Correct Answer: C — 70°C
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Q. What is the final volume when 100 mL of a 3 M solution is diluted to a concentration of 1 M? (2022) 2022
A.
300 mL
B.
200 mL
C.
100 mL
D.
150 mL
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Solution
Using the dilution formula C1V1 = C2V2, we have 3 M * 100 mL = 1 M * V2. Thus, V2 = 300 mL.
Correct Answer: A — 300 mL
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Q. What is the first derivative of f(x) = e^(2x)?
A.
2e^(2x)
B.
e^(2x)
C.
e^(x)
D.
2x*e^(2x)
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Solution
Using the chain rule, f'(x) = 2e^(2x).
Correct Answer: A — 2e^(2x)
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Q. What is the first derivative of f(x) = ln(x)? (2019)
A.
1/x
B.
x
C.
ln(x)
D.
e^x
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Solution
The derivative f'(x) = 1/x.
Correct Answer: A — 1/x
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Q. What is the first derivative of f(x) = tan(x)? (2021)
A.
sec^2(x)
B.
cos^2(x)
C.
sin^2(x)
D.
csc^2(x)
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Solution
The derivative of f(x) = tan(x) is f'(x) = sec^2(x).
Correct Answer: A — sec^2(x)
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Q. What is the first law of thermodynamics?
A.
Energy cannot be created or destroyed
B.
Entropy of an isolated system always increases
C.
Heat cannot spontaneously flow from a colder body to a hotter body
D.
The total energy of a system is constant
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Solution
The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another.
Correct Answer: A — Energy cannot be created or destroyed
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Q. What is the first step in effective reading comprehension?
A.
Reading the questions first
B.
Previewing the text
C.
Highlighting key points
D.
Taking notes
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Solution
Previewing the text is the first step in effective reading comprehension as it provides an overview of the content.
Correct Answer: B — Previewing the text
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Q. What is the first step in the reading comprehension process? (2021)
A.
Reading the text
B.
Identifying the main idea
C.
Making predictions
D.
Summarizing the text
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Solution
The first step in the reading comprehension process is to read the text thoroughly to understand its content.
Correct Answer: A — Reading the text
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Q. What is the focal length of a concave lens if it forms a virtual image at a distance of 20 cm from the lens?
A.
-10 cm
B.
-20 cm
C.
10 cm
D.
20 cm
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Solution
For a concave lens, the focal length (f) is negative. The virtual image distance (v) is -20 cm. Using the lens formula 1/f = 1/v + 1/u, we can find f. Since v = -20 cm, we can assume u is at infinity, thus 1/f = 1/(-20) + 0, giving f = -20 cm.
Correct Answer: B — -20 cm
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Q. What is the focal length of a concave lens with a focal point at -15 cm?
A.
15 cm
B.
-15 cm
C.
30 cm
D.
-30 cm
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Solution
The focal length of a concave lens is negative, so it is -15 cm.
Correct Answer: B — -15 cm
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Q. What is the focal length of a concave lens with a power of -2 diopters?
A.
-0.5 m
B.
0.5 m
C.
-2 m
D.
2 m
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Solution
Power (P) = 1/focal length (f). Therefore, f = 1/P = 1/(-2) = -0.5 m.
Correct Answer: A — -0.5 m
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Q. What is the focal length of a concave mirror if an object is placed at a distance of 30 cm from the mirror and the image is formed at a distance of 15 cm from the mirror?
A.
10 cm
B.
15 cm
C.
20 cm
D.
25 cm
Show solution
Solution
Using the mirror formula, 1/f = 1/v + 1/u. Here, v = -15 cm (real image) and u = -30 cm (object distance). Thus, 1/f = 1/(-15) + 1/(-30) = -1/10, so f = -10 cm.
Correct Answer: A — 10 cm
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Q. What is the focal length of a concave mirror if an object placed 30 cm in front of it produces an image at 10 cm in front of the mirror?
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
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Solution
Using the mirror formula 1/f = 1/v + 1/u, where u = -30 cm and v = -10 cm, we find f = 15 cm.
Correct Answer: C — 15 cm
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Q. What is the focal length of a concave mirror if an object placed at a distance of 30 cm produces an image at a distance of 15 cm?
A.
10 cm
B.
15 cm
C.
20 cm
D.
25 cm
Show solution
Solution
Using the mirror formula, 1/f = 1/v + 1/u; here, v = -15 cm (real image) and u = -30 cm. Thus, 1/f = 1/(-15) + 1/(-30) = -1/10, so f = 10 cm.
Correct Answer: A — 10 cm
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Q. What is the focal length of a concave mirror if an object placed at a distance of 30 cm produces an image at a distance of 10 cm? (2021)
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
Show solution
Solution
Using the mirror formula, 1/f = 1/v + 1/u; here, v = -10 cm (real image) and u = -30 cm (object distance). Thus, 1/f = 1/(-10) + 1/(-30) = -1/6, so f = 5 cm.
Correct Answer: A — 5 cm
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Q. What is the focal length of a concave mirror if the object distance is 30 cm and the image distance is 15 cm? (2021)
A.
10 cm
B.
15 cm
C.
20 cm
D.
25 cm
Show solution
Solution
Using the mirror formula, 1/f = 1/v + 1/u. Here, v = -15 cm (real image) and u = -30 cm (object distance). Thus, 1/f = 1/(-15) + 1/(-30) = -1/10, so f = -10 cm.
Correct Answer: A — 10 cm
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Q. What is the focal length of a concave mirror if the object is placed at a distance of 30 cm and the image is formed at a distance of 15 cm from the mirror? (2021)
A.
10 cm
B.
15 cm
C.
20 cm
D.
25 cm
Show solution
Solution
Using the mirror formula, 1/f = 1/v + 1/u. Here, v = -15 cm (image distance is negative for concave mirror) and u = -30 cm. Therefore, 1/f = 1/(-15) + 1/(-30) = -1/10. Thus, f = 10 cm.
Correct Answer: A — 10 cm
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Q. What is the focal length of a convex lens if it forms a real image at a distance of 30 cm when the object is placed at 15 cm from the lens?
A.
10 cm
B.
15 cm
C.
20 cm
D.
25 cm
Show solution
Solution
Using the lens formula 1/f = 1/v - 1/u, where v = 30 cm and u = -15 cm, we find f = 20 cm.
Correct Answer: C — 20 cm
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Q. What is the focal length of a diverging lens if the image distance is -15 cm and the object distance is -10 cm? (2023)
A.
-30 cm
B.
-20 cm
C.
-15 cm
D.
-10 cm
Show solution
Solution
Using the lens formula 1/f = 1/v - 1/u, we find f = -20 cm.
Correct Answer: B — -20 cm
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Q. What is the focal length of a lens if it forms a virtual image at a distance of 15 cm when the object is placed at 10 cm?
A.
-30 cm
B.
30 cm
C.
15 cm
D.
10 cm
Show solution
Solution
Using the lens formula 1/f = 1/v - 1/u, we have 1/f = 1/(-15) - 1/(-10) = -1/15 + 1/10 = -1/30, thus f = -30 cm.
Correct Answer: A — -30 cm
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Q. What is the focal length of a lens if it forms a virtual image at a distance of 12 cm when the object is placed at 8 cm?
A.
-24 cm
B.
-12 cm
C.
12 cm
D.
24 cm
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Solution
Using the lens formula, we find the focal length to be -12 cm.
Correct Answer: B — -12 cm
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Q. What is the focal length of a lens if it forms an image at infinity when the object is placed at 30 cm?
A.
30 cm
B.
15 cm
C.
60 cm
D.
20 cm
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Solution
For the image to be at infinity, the focal length must be equal to the object distance, hence f = 60 cm.
Correct Answer: C — 60 cm
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Q. What is the focal length of a lens that forms a virtual image at a distance of 20 cm when the object is placed at 10 cm?
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
Show solution
Solution
Using the lens formula, 1/f = 1/v - 1/u. Here, v = -20 cm (virtual image), u = -10 cm. Solving gives f = 5 cm.
Correct Answer: A — 5 cm
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Q. What is the focal length of a plano-convex lens with a radius of curvature of 30 cm?
A.
15 cm
B.
30 cm
C.
45 cm
D.
60 cm
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Solution
Using the lens maker's formula for a plano-convex lens, f = R/2 = 30 cm / 2 = 30 cm.
Correct Answer: B — 30 cm
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Q. What is the focus of the Beti Bachao Beti Padhao scheme? (2015)
A.
Promoting women's entrepreneurship
B.
Saving the girl child and educating her
C.
Providing healthcare to women
D.
Increasing women's participation in politics
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Solution
Beti Bachao Beti Padhao focuses on saving the girl child and ensuring her education.
Correct Answer: B — Saving the girl child and educating her
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Q. What is the focus of the parabola defined by the equation y^2 = 20x?
A.
(5, 0)
B.
(0, 5)
C.
(0, 10)
D.
(10, 0)
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Solution
In the equation y^2 = 4px, we have 4p = 20, thus p = 5. The focus is at (5, 0).
Correct Answer: A — (5, 0)
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Q. What is the focus of the parabola given by the equation y^2 = 20x?
A.
(5, 0)
B.
(0, 5)
C.
(0, -5)
D.
(10, 0)
Show solution
Solution
For the parabola y^2 = 4px, here 4p = 20, so p = 5. The focus is at (5, 0).
Correct Answer: A — (5, 0)
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