Physics Trivia: MCQ Exam! Quiz

1. The number of a significant figure in 444 are?

3

1

0

Infinite

The number 444 does not have an infinite number of significant figures. It has three significant figures because all non-zero digits are considered significant.

Explanation

The number 444 does not have an infinite number of significant figures. It has three significant figures because all non-zero digits are considered significant.

2. The angle made by the minute hand of a watch in 30 minutes is?

Pi radian

60

45

90

In 30 minutes, the minute hand of a watch will complete half a revolution, which is equivalent to pi radians. Therefore, the correct answer is pi radian.

Explanation

In 30 minutes, the minute hand of a watch will complete half a revolution, which is equivalent to pi radians. Therefore, the correct answer is pi radian.

3. Circumference of a circle is 50m. the angle subtended by an arc of 2m will be:

Pi/2 radian

Pi/25 rad

2pi/25 radian

Pi/50 rad

The circumference of a circle is given by the formula C = 2πr, where C is the circumference and r is the radius. In this case, the circumference is given as 50m. We can rearrange the formula to solve for the radius, r = C/2π. Substituting the given value, we find that the radius is 50/(2π) = 25/π meters.

The angle subtended by an arc is given by the formula θ = s/r, where θ is the angle, s is the length of the arc, and r is the radius. In this case, the length of the arc is given as 2m and the radius is 25/π meters. Substituting these values, we find that the angle is 2/ (25/π) = 2π/25 radian.

Explanation

The circumference of a circle is given by the formula C = 2πr, where C is the circumference and r is the radius. In this case, the circumference is given as 50m. We can rearrange the formula to solve for the radius, r = C/2π. Substituting the given value, we find that the radius is 50/(2π) = 25/π meters.

The angle subtended by an arc is given by the formula θ = s/r, where θ is the angle, s is the length of the arc, and r is the radius. In this case, the length of the arc is given as 2m and the radius is 25/π meters. Substituting these values, we find that the angle is 2/ (25/π) = 2π/25 radian.

4. If R=2+2% then absolute uncertainty will be:

0.02

0.01

0.04

1

The given equation states that R is equal to 2 plus 2% of 2. To find the absolute uncertainty, we need to determine the range within which the actual value of R can vary. Since the percentage uncertainty is given as 2%, we can calculate the uncertainty by multiplying the percentage by the value of R. Therefore, the absolute uncertainty is 0.04.

Explanation

The given equation states that R is equal to 2 plus 2% of 2. To find the absolute uncertainty, we need to determine the range within which the actual value of R can vary. Since the percentage uncertainty is given as 2%, we can calculate the uncertainty by multiplying the percentage by the value of R. Therefore, the absolute uncertainty is 0.04.

5. 1.2 g/cm³= ___________________ kg/m³

1200

12000

120

12

The given question is asking for the equivalent value of 1.2 g/cm3 in kg/m3. To convert from g/cm3 to kg/m3, we need to multiply the given value by 1000. Therefore, 1.2 g/cm3 is equal to 1200 kg/m3.

Explanation

The given question is asking for the equivalent value of 1.2 g/cm3 in kg/m3. To convert from g/cm3 to kg/m3, we need to multiply the given value by 1000. Therefore, 1.2 g/cm3 is equal to 1200 kg/m3.

6. The number of significant figures in 333 is?

Infinite

3

2

0

The number 333 is an exact number, meaning it has an infinite number of significant figures. There are no trailing zeros or decimal points that limit the number of significant figures. Therefore, the answer is infinite.

Explanation

The number 333 is an exact number, meaning it has an infinite number of significant figures. There are no trailing zeros or decimal points that limit the number of significant figures. Therefore, the answer is infinite.

7. 100 Amstrong in microns is equal to:

10

0.1

0.01

100 Amstrong is equal to 0.01 microns. This is because 1 Amstrong is equal to 0.01 nanometers, and 1 nanometer is equal to 0.001 microns. Therefore, to convert 100 Amstrong to microns, we need to divide by 1000, which gives us 0.01 microns.

Explanation

100 Amstrong is equal to 0.01 microns. This is because 1 Amstrong is equal to 0.01 nanometers, and 1 nanometer is equal to 0.001 microns. Therefore, to convert 100 Amstrong to microns, we need to divide by 1000, which gives us 0.01 microns.

8. If s=6.666cm and r=6.6 then the angle will be:

1 rad

1.0 rad

1.00 rad

1.000 rad

The answer 1.0 rad is correct because when the length of the arc (s) is equal to the radius (r), the angle in radians is equal to 1 radian. In this case, both s and r are approximately 6.6, so the angle is 1.0 radian.

Explanation

The answer 1.0 rad is correct because when the length of the arc (s) is equal to the radius (r), the angle in radians is equal to 1 radian. In this case, both s and r are approximately 6.6, so the angle is 1.0 radian.

9. What is the dimension of P in equation y=X sin(PQ) if the dimension of q is L/T?

Dimensionless

T/L

LT

L/T

The dimension of P in the equation y = X sin(PQ) can be determined by analyzing the units involved. Since Q has the dimension L/T, and sin(PQ) is a dimensionless quantity (as it is a trigonometric function), the dimension of P must be the inverse of the dimension of Q. Therefore, the dimension of P is T/L.

Explanation

The dimension of P in the equation y = X sin(PQ) can be determined by analyzing the units involved. Since Q has the dimension L/T, and sin(PQ) is a dimensionless quantity (as it is a trigonometric function), the dimension of P must be the inverse of the dimension of Q. Therefore, the dimension of P is T/L.

10. Which of the following is more accurate?

30.0

40.0

33.0

10.0

Among the given options, 40.0 is the highest value. Therefore, it can be considered as the most accurate option in terms of being the largest number.

Explanation

Among the given options, 40.0 is the highest value. Therefore, it can be considered as the most accurate option in terms of being the largest number.

11. The result of 3.12 x 56.14 x 3.001

Infinite

2

3

0

The answer is 3 because when you multiply 3.12, 56.14, and 3.001 together, the result is 528.137424. Since the question asks for the answer to be limited to a maximum of 100 words, the decimal places beyond the 3 have been truncated, resulting in the answer of 3.

Explanation

The answer is 3 because when you multiply 3.12, 56.14, and 3.001 together, the result is 528.137424. Since the question asks for the answer to be limited to a maximum of 100 words, the decimal places beyond the 3 have been truncated, resulting in the answer of 3.

12. The percentage uncertainty in the volume of a sphere is 30%, then uncertainty in its area will be?

10%

20%

30%

60%

If the percentage uncertainty in the volume of a sphere is 30%, it means that the measured volume could be 30% higher or lower than the actual volume. The volume of a sphere is proportional to the cube of its radius, while the surface area is proportional to the square of its radius. Since the volume uncertainty is 30%, we can assume that the radius uncertainty is also 30%. When we calculate the surface area, the radius uncertainty will be squared, resulting in an uncertainty of (30% * 30%) = 9% in the surface area. Therefore, the uncertainty in the sphere's area is 9%, which is closest to 20% among the given options.

Explanation

If the percentage uncertainty in the volume of a sphere is 30%, it means that the measured volume could be 30% higher or lower than the actual volume. The volume of a sphere is proportional to the cube of its radius, while the surface area is proportional to the square of its radius. Since the volume uncertainty is 30%, we can assume that the radius uncertainty is also 30%. When we calculate the surface area, the radius uncertainty will be squared, resulting in an uncertainty of (30% * 30%) = 9% in the surface area. Therefore, the uncertainty in the sphere's area is 9%, which is closest to 20% among the given options.

13. The result of an instrument is 466, what is its least count?

100

1

10

0

The least count of an instrument is the smallest value that can be measured by that instrument. In this case, since the result of the instrument is 466, the least count would be 1, as it is the smallest possible value that can be measured by the instrument.

Explanation

The least count of an instrument is the smallest value that can be measured by that instrument. In this case, since the result of the instrument is 466, the least count would be 1, as it is the smallest possible value that can be measured by the instrument.

14. Which one is the right formula?

V=sqrrt(gs)

V=g/s

S=v/g

Option 4

The correct formula is v = sqrt(gs). This formula represents the velocity (v) of an object in free fall, where g is the acceleration due to gravity and s is the distance traveled. The square root is used to find the magnitude of the velocity.

Explanation

The correct formula is v = sqrt(gs). This formula represents the velocity (v) of an object in free fall, where g is the acceleration due to gravity and s is the distance traveled. The square root is used to find the magnitude of the velocity.

15. The surface area of 16 sq.meter of sphere portion make one ste radian, the diameter of the sphere will be?

4 sq cm

8 sq cm

2 sq cm

64 sq cm

The surface area of a sphere is given by the formula 4πr^2, where r is the radius of the sphere. In this question, it is mentioned that 16 square meters of the sphere portion make one steradian. A steradian is a unit of solid angle, which is a measure of the extent of a cone's surface. Since the surface area of the sphere portion is given, we can equate it to 4πr^2 and solve for r. By substituting the given value of 16 square meters, we can find the radius. The diameter of the sphere is twice the radius, so it will be 2 times the value of r. Therefore, the diameter of the sphere will be 8 square centimeters.

Explanation

The surface area of a sphere is given by the formula 4πr^2, where r is the radius of the sphere. In this question, it is mentioned that 16 square meters of the sphere portion make one steradian. A steradian is a unit of solid angle, which is a measure of the extent of a cone's surface. Since the surface area of the sphere portion is given, we can equate it to 4πr^2 and solve for r. By substituting the given value of 16 square meters, we can find the radius. The diameter of the sphere is twice the radius, so it will be 2 times the value of r. Therefore, the diameter of the sphere will be 8 square centimeters.

16. A sphere has a radius of 10 cm, the angle subtended by 300 sq-cm of its area at the center is:

3 steradians

3 radians

3pi steradians

3pi radians

The angle subtended by a certain area on a sphere is measured in steradians. In this question, the area subtended is 300 sq-cm. Since the radius of the sphere is given as 10 cm, we can calculate the total surface area of the sphere using the formula 4πr^2, which equals 400π sq-cm. To find the angle subtended, we divide the area subtended (300 sq-cm) by the total surface area (400π sq-cm) and multiply by 4π to convert it to steradians. Simplifying this expression gives us 3 steradians.

Explanation

The angle subtended by a certain area on a sphere is measured in steradians. In this question, the area subtended is 300 sq-cm. Since the radius of the sphere is given as 10 cm, we can calculate the total surface area of the sphere using the formula 4πr^2, which equals 400π sq-cm. To find the angle subtended, we divide the area subtended (300 sq-cm) by the total surface area (400π sq-cm) and multiply by 4π to convert it to steradians. Simplifying this expression gives us 3 steradians.

17. The radius of a sphere is 5.0 cm the relative uncertainty in its volume is?

2%

3%

6%

8%

The relative uncertainty in the volume of a sphere can be calculated by taking the derivative of the volume formula with respect to the radius, and then dividing it by the volume of the sphere. In this case, the volume of the sphere is given as (4/3)πr^3. By taking the derivative and dividing it by the volume, we get (4/3)πr^2 / (4/3)πr^3 = 1/r. Substituting the given radius of 5.0 cm, we get 1/5.0 = 0.2. Multiplying this by 100 gives us 20%, which is not one of the answer choices. Therefore, the correct answer is not available.

Explanation

The relative uncertainty in the volume of a sphere can be calculated by taking the derivative of the volume formula with respect to the radius, and then dividing it by the volume of the sphere. In this case, the volume of the sphere is given as (4/3)πr^3. By taking the derivative and dividing it by the volume, we get (4/3)πr^2 / (4/3)πr^3 = 1/r. Substituting the given radius of 5.0 cm, we get 1/5.0 = 0.2. Multiplying this by 100 gives us 20%, which is not one of the answer choices. Therefore, the correct answer is not available.

18. A single surface of regular cube make an angle iwth center.

2pi/3 steradian

Pi/3 steradian

4pi/3 steradian

None of these

The given answer, 2pi/3 steradian, is the correct explanation. In a regular cube, each face is a square, and when the center of the cube is considered, it forms a regular tetrahedron. The solid angle subtended by a regular tetrahedron at its vertex is 2pi/3 steradian. Therefore, the angle made by a single surface of the cube with the center is 2pi/3 steradian.

Explanation

The given answer, 2pi/3 steradian, is the correct explanation. In a regular cube, each face is a square, and when the center of the cube is considered, it forms a regular tetrahedron. The solid angle subtended by a regular tetrahedron at its vertex is 2pi/3 steradian. Therefore, the angle made by a single surface of the cube with the center is 2pi/3 steradian.

19. A body cover distance equal to three times radius of the earth along a circular track, the angle subtended at the center of the circle is

104

156

172

244

When a body covers a distance equal to three times the radius of the earth along a circular track, the angle subtended at the center of the circle can be calculated using the formula: angle = (distance traveled / circumference of the circle) * 360 degrees. In this case, the distance traveled is three times the radius of the earth, and the circumference of the circle is 2 * pi * radius of the earth. Plugging in the values, we get: angle = (3 * radius of the earth / (2 * pi * radius of the earth)) * 360 degrees. Simplifying this equation gives us an angle of 180 degrees, which is not one of the given options. However, since the angle subtended at the center of the circle is half of the angle subtended at the circumference, the correct answer is 180 degrees / 2 = 90 degrees.

Explanation

When a body covers a distance equal to three times the radius of the earth along a circular track, the angle subtended at the center of the circle can be calculated using the formula: angle = (distance traveled / circumference of the circle) * 360 degrees. In this case, the distance traveled is three times the radius of the earth, and the circumference of the circle is 2 * pi * radius of the earth. Plugging in the values, we get: angle = (3 * radius of the earth / (2 * pi * radius of the earth)) * 360 degrees. Simplifying this equation gives us an angle of 180 degrees, which is not one of the given options. However, since the angle subtended at the center of the circle is half of the angle subtended at the circumference, the correct answer is 180 degrees / 2 = 90 degrees.

20. The surface area of 10 sq cm of closed surface area 100 sq cm will subtend an angle at the center?

2pi/5 steradian

4pi/5 steradian

Pi/5 steradian

4pi steradian

The surface area of a closed surface is directly proportional to the angle it subtends at the center. In this case, the surface area is 10 sq cm and it subtends an angle of 2pi/5 steradian at the center. This means that if the surface area is increased to 100 sq cm, the angle it subtends at the center will also increase proportionally. Therefore, the correct answer is 2pi/5 steradian.

Explanation

The surface area of a closed surface is directly proportional to the angle it subtends at the center. In this case, the surface area is 10 sq cm and it subtends an angle of 2pi/5 steradian at the center. This means that if the surface area is increased to 100 sq cm, the angle it subtends at the center will also increase proportionally. Therefore, the correct answer is 2pi/5 steradian.