Q. If the center of a circle is at (0, 0) and it passes through the point (3, 4), what is the equation of the circle?
A.
x² + y² = 25
B.
x² + y² = 12
C.
x² + y² = 7
D.
x² + y² = 16
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Solution
The radius is 5 (distance from (0,0) to (3,4)), so the equation is x² + y² = 5² = 25.
Correct Answer:
A
— x² + y² = 25
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Q. If the center of a circle is at (0, 0) and it passes through the point (3, 4), what is the radius of the circle?
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Solution
The radius is the distance from the center to the point, which is √(3² + 4²) = √25 = 5.
Correct Answer:
A
— 5
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Q. If the center of a circle is at (3, 4) and it passes through the point (7, 1), what is the radius? (2019)
A.
5 units
B.
4 units
C.
3 units
D.
6 units
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Solution
Radius = distance from center to point = √[(7-3)² + (1-4)²] = √[16 + 9] = √25 = 5 units.
Correct Answer:
A
— 5 units
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Q. If the chance of contracting a disease is 1 in 500, what is the percentage chance of not contracting the disease? (2023)
A.
99.8%
B.
99.9%
C.
98.5%
D.
97.5%
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Solution
The chance of not contracting the disease = 1 - (1/500) = 499/500 = 0.998 = 99.8%.
Correct Answer:
B
— 99.9%
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Q. If the charge density of a non-conducting sphere increases linearly with radius, how does the electric field vary inside the sphere?
A.
Linearly with radius
B.
Quadratically with radius
C.
Constant
D.
Inversely with radius
Show solution
Solution
The electric field inside a non-conducting sphere with linearly increasing charge density varies linearly with radius.
Correct Answer:
A
— Linearly with radius
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Q. If the charge density of a non-uniform spherical charge distribution varies as ρ(r) = kr², what is the electric field at the center of the sphere?
A.
0
B.
k/3ε₀
C.
k/4ε₀
D.
k/2ε₀
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Solution
At the center of a non-uniform spherical charge distribution, the electric field is zero due to symmetry.
Correct Answer:
A
— 0
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Q. If the charge density of a spherical charge distribution increases linearly with radius, how does the electric field vary inside the sphere?
A.
Linearly with radius
B.
Quadratically with radius
C.
Inversely with radius
D.
Constant
Show solution
Solution
The electric field inside a non-uniform charge distribution varies quadratically with radius due to the increasing charge density.
Correct Answer:
B
— Quadratically with radius
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Q. If the charge inside a closed surface is doubled, what happens to the electric flux through the surface?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It becomes zero
Show solution
Solution
According to Gauss's law, the electric flux is directly proportional to the enclosed charge, so it doubles.
Correct Answer:
A
— It doubles
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Q. If the charge on a capacitor is doubled while keeping the voltage constant, what happens to the capacitance? (2022)
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
Capacitance C = Q/V. If Q is doubled and V remains constant, C must also double.
Correct Answer:
A
— It doubles
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Q. If the charge on a capacitor is doubled while the voltage remains constant, what happens to the capacitance?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
Show solution
Solution
Capacitance C = Q/V; if Q is doubled and V remains constant, C must halve.
Correct Answer:
B
— It halves
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Q. If the charge on a capacitor is doubled, what happens to the electric field between the plates? (2022)
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
The electric field E between the plates of a capacitor is directly proportional to the charge. If the charge is doubled, the electric field also doubles.
Correct Answer:
A
— It doubles
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Q. If the charge on a capacitor is doubled, what happens to the energy stored in it?
A.
It doubles
B.
It quadruples
C.
It remains the same
D.
It halves
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Solution
The energy stored in a capacitor is given by U = 1/2 * C * V^2. If the charge is doubled, the energy stored quadruples.
Correct Answer:
B
— It quadruples
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Q. If the charge on a capacitor is doubled, what happens to the energy stored? (2019)
A.
It remains the same
B.
It doubles
C.
It quadruples
D.
It halves
Show solution
Solution
The energy stored in a capacitor is proportional to the square of the charge (U = Q^2/(2C)). Doubling the charge increases the energy by a factor of 4.
Correct Answer:
C
— It quadruples
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Q. If the charge on an object is tripled, what happens to the electric field produced by that charge? (2020)
A.
It triples
B.
It halves
C.
It remains the same
D.
It quadruples
Show solution
Solution
The electric field E is directly proportional to the charge, so tripling the charge will triple the electric field.
Correct Answer:
A
— It triples
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Q. If the circumference of a circle is 31.4 cm, what is its radius? (2022)
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
Show solution
Solution
Circumference = 2πr; 31.4 = 2 * π * r; r = 5 cm.
Correct Answer:
A
— 5 cm
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Q. If the circumference of a circle is 31.4 cm, what is its radius? (Use π = 3.14) (2015)
A.
5 cm
B.
7 cm
C.
10 cm
D.
8 cm
Show solution
Solution
Circumference = 2πr, so r = circumference / (2π) = 31.4 / (2 * 3.14) = 5 cm.
Correct Answer:
A
— 5 cm
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Q. If the circumference of a circle is 31.4 cm, what is the radius of the circle? (Use π = 3.14) (2022)
A.
5 cm
B.
7 cm
C.
10 cm
D.
15 cm
Show solution
Solution
Circumference = 2πr. Therefore, r = circumference / (2π) = 31.4 / (2 * 3.14) = 5 cm.
Correct Answer:
A
— 5 cm
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Q. If the circumference of a circle is 31.4 cm, what is the radius?
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
Show solution
Solution
Using the formula C = 2πr, we find r = C/(2π) = 31.4/(2*3.14) = 5 cm.
Correct Answer:
A
— 5 cm
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Q. If the circumference of a circle is 31.4 cm, what is the radius? (2020) 2020
A.
5 cm
B.
10 cm
C.
15 cm
D.
20 cm
Show solution
Solution
Circumference = 2πr. Therefore, r = Circumference / (2π) = 31.4 cm / (2 * 3.14) = 5 cm.
Correct Answer:
A
— 5 cm
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Q. If the circumference of a circle is 31.4 units, what is its radius? (Use π = 3.14) (2020)
Show solution
Solution
Circumference = 2πr. Setting 31.4 = 2 × 3.14 × r gives r = 5 units.
Correct Answer:
A
— 5
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Q. If the circumference of a circle is 31.4 units, what is the radius? (Use π = 3.14) (2020)
Show solution
Solution
The circumference C = 2πr. Setting 31.4 = 2 * 3.14 * r gives r = 5.
Correct Answer:
A
— 5
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Q. If the circumference of a circle is measured as 31.4 cm with an error of 0.2 cm, what is the radius?
A.
5 cm
B.
4.5 cm
C.
5.0 cm
D.
6 cm
Show solution
Solution
Circumference = 2πr. Measured circumference = 31.4 cm. Thus, r = 31.4 / (2π) ≈ 5.0 cm.
Correct Answer:
C
— 5.0 cm
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Q. If the circumference of a circle is measured as 31.4 cm with an error of 0.2 cm, what is the percentage error?
A.
0.64%
B.
0.5%
C.
1%
D.
0.2%
Show solution
Solution
Percentage error = (Absolute error / Measured value) * 100 = (0.2 / 31.4) * 100 ≈ 0.64%.
Correct Answer:
A
— 0.64%
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Q. If the circumradius of triangle ABC is 10 cm and the area is 48 cm², what is the length of the side opposite to angle A?
A.
12 cm
B.
14 cm
C.
16 cm
D.
18 cm
Show solution
Solution
Using the formula R = (abc)/(4 * Area), we can find the side opposite to angle A. Let a = side opposite to A. Then, a = (4 * Area * R) / (bc) = (4 * 48 * 10) / (b * c).
Correct Answer:
B
— 14 cm
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Q. If the circumradius R of triangle ABC is 5 cm, what is the maximum area of the triangle?
A.
12.5 cm²
B.
15 cm²
C.
20 cm²
D.
25 cm²
Show solution
Solution
The maximum area of a triangle with circumradius R is given by the formula Area = (abc)/(4R). For maximum area, the triangle should be equilateral, thus Area = (3√3/4) * (R^2) = (3√3/4) * (5^2) = 25√3/4 cm².
Correct Answer:
C
— 20 cm²
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Q. If the coefficient of x^k in the expansion of (x + 1)^n is given by C(n,k), what does C(n,k) represent?
A.
The number of ways to choose k items from n.
B.
The total number of terms in the expansion.
C.
The sum of the coefficients.
D.
The product of the coefficients.
Show solution
Solution
C(n,k) represents the number of ways to choose k items from n, which corresponds to the coefficient of x^k.
Correct Answer:
A
— The number of ways to choose k items from n.
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Q. If the common ratio of a GP is negative, which of the following statements is true?
A.
The terms will always be positive.
B.
The terms will alternate in sign.
C.
The sum of the terms will be negative.
D.
The first term must be negative.
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Solution
In a GP with a negative common ratio, the terms will alternate in sign, starting from the sign of the first term.
Correct Answer:
B
— The terms will alternate in sign.
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Q. If the compound interest on a sum of money for 2 years at 10% per annum is $220, what is the principal amount?
A.
$2000
B.
$1800
C.
$1500
D.
$2500
Show solution
Solution
Let the principal be P. Then, CI = P(1 + r)^n - P = P(1.1^2 - 1) = 220. Solving gives P = $2000.
Correct Answer:
A
— $2000
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Q. If the compound interest on a sum of money for 2 years is $400 and the principal is $1600, what is the rate of interest? (2023)
A.
10%
B.
12.5%
C.
15%
D.
20%
Show solution
Solution
Using the formula CI = P[(1 + r)^n - 1], we can set up the equation 400 = 1600[(1 + r)^2 - 1]. Solving gives r = 12.5%.
Correct Answer:
B
— 12.5%
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Q. If the concentration of a reactant is increased in a system at equilibrium, what will happen according to Le Chatelier's principle?
A.
The equilibrium will shift to the right.
B.
The equilibrium will shift to the left.
C.
The equilibrium will not change.
D.
The reaction will stop.
Show solution
Solution
According to Le Chatelier's principle, if a change is made to a system at equilibrium, the system will adjust to counteract that change. Increasing the concentration of a reactant will shift the equilibrium to the right, favoring the formation of products.
Correct Answer:
A
— The equilibrium will shift to the right.
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