In C4 plants, the first stable compound formed during carbon fixation is:

The correct answer is B: Oxaloacetate. In C4 photosynthesis, CO2 combines with PEP (3-carbon) to form oxaloacetate (4-carbon compound) via the enzyme PEP carboxylase.

An electron undergoes a transition from n=3 to n=1 in a hydrogen atom. Which series does this transition belong to?

The correct answer is C: Lyman series. The Lyman series involves transitions to n=1 from higher energy levels. Balmer series ends at n=2, Paschen at n=3, and Brackett at n=4.

Which celestial phenomenon occurs when the Moon passes between the Earth and the Sun, blocking the Sun's light and casting a shadow on Earth?

The correct answer is A: Solar Eclipse. A solar eclipse happens when the Moon's orbit places it directly between Earth and the Sun, creating a shadow on Earth's surface. This is distinct from a lunar eclipse where Earth blocks sunlight from reaching the Moon, and from penumbral or annular eclipses which are specific types with different c

Which of the following elements has the highest electronegativity value on the Pauling scale?

The correct answer is A: Fluorine. Fluorine has the highest electronegativity value of 3.98 on the Pauling scale, making it the most electronegative element. This is because it has the smallest atomic radius and the highest effective nuclear charge among all elements, causing it to attract electrons most strongly in a chemical bond.

Which phenomenon explains why stars twinkle but planets do not?

The correct answer is B: Point sources vs extended sources in atmospheric turbulence. Stars appear as point sources. Turbulent layers in the atmosphere refract starlight randomly, causing intensity variations (twinkling). Planets appear as extended sources, so refraction averaging effect minimizes visible twinkling.

Home

Home › Subjects › General Science › Physics

General Science
Physics

Physics, Chemistry, Biology and more

53 Q 8 Topics Take Mock Test

Difficulty: All Easy Medium Hard 21–30 of 53

Topics in General Science

All Physics 106 Chemistry 9 Biology 2 Botany 78 Human Body 4 Disease & Health 2 Space & Astronomy 5 Environment 1

Q.21 Medium Physics

A spring with spring constant k = 100 N/m is compressed by 0.1 m. What is the elastic potential energy stored?

A 0.5 J

B 1 J

C 5 J

D 10 J

Correct Answer: A. 0.5 J

EXPLANATION

Elastic PE = ½kx² = ½ × 100 × (0.1)² = ½ × 100 × 0.01 = 0.5 J.

Test

Q.22 Medium Physics

A block slides down a frictionless incline of angle 30°. What is its acceleration down the incline?

A 4.9 m/s²

B 8.66 m/s²

C 9.8 m/s²

D 10 m/s²

Correct Answer: A. 4.9 m/s²

EXPLANATION

When a block slides down a frictionless incline, gravity's component along the slope determines the acceleration.

Step 1: [Identify the Force Component Along the Incline]

On an incline, gravity acts vertically downward, but only its component parallel to the slope causes acceleration down the incline.

F_{\parallel} = mg\sin(\theta)

Step 2: [Apply Newton's Second Law]

Using F = ma, the net force along the incline equals mass times acceleration. The mass cancels out, giving us a pure kinematic result.

a = g\sin(\theta) = 9.8 \times \sin(30°) = 9.8 \times 0.5 = 4.9 \text{ m/s}^2

The acceleration down the incline is 4.9 m/s² (Answer: A)

Test

Q.23 Medium Physics

Two identical objects moving with velocities v and 2v collide and stick together. What fraction of kinetic energy is lost?

A 1/3

B 2/3

C 1/2

D 2/5

Correct Answer: B. 2/3

EXPLANATION

Initial KE = ½m(v)² + ½m(2v)² = 2.5mv². Final velocity = 3v/2 (by momentum conservation). Final KE = ½(2m)(3v/2)² = 2.25mv²/4 = 0.84mv². Loss = 2.5 - 0.84 = 1.66, which is 2/3 of initial KE.

Test

Q.24 Medium Physics

A conducting sphere is given a charge of 8 μC. What is the electric field at its surface if the radius is 2 cm?

A 1.8 × 10⁶ N/C

B 3.6 × 10⁷ N/C

C 1.8 × 10⁷ N/C

D 7.2 × 10⁷ N/C

Correct Answer: C. 1.8 × 10⁷ N/C

EXPLANATION

Electric field at surface: E = kQ/r² = (9 × 10⁹ × 8 × 10⁻⁶)/(0.02)² = (72)/(4 × 10⁻⁴) = 1.8 × 10⁷ N/C.

Test

Q.25 Medium Physics

A submarine sonar uses ultrasound with frequency 50 kHz and speed 1500 m/s in water. What is the wavelength?

A 0.03 m

B 0.3 m

C 3 m

D 30 m

Correct Answer: A. 0.03 m

EXPLANATION

Wavelength λ = v/f = 1500/(50 × 10³) = 1500/50000 = 0.03 m = 3 cm. Higher frequencies in denser mediums produce shorter wavelengths.

Test

Q.26 Medium Physics

An object undergoes simple harmonic motion with amplitude 5 cm and frequency 2 Hz. What is the maximum velocity?

A 10π cm/s

B 20π cm/s

C 5π cm/s

D 2.5π cm/s

Correct Answer: B. 20π cm/s

EXPLANATION

Maximum velocity in SHM: v_max = ωA = 2πfA = 2π × 2 × 5 = 20π cm/s ≈ 62.8 cm/s.

Test

Q.27 Medium Physics

A radioactive element has a half-life of 10 years. What fraction of the original sample remains after 30 years?

A 1/2

B 1/4

C 1/8

D 3/4

Correct Answer: C. 1/8

EXPLANATION

After 30 years = 3 half-lives: N = N₀ × (1/2)³ = N₀/8. The sample reduces by half three times successively.

Test

Q.28 Medium Physics

A 10 m long ladder leans against a vertical wall at 60° to the ground. How high does it reach on the wall?

A 5 m

B 5√3 m or 8.66 m

C 10√3 m

D 10/√3 m

Correct Answer: B. 5√3 m or 8.66 m

EXPLANATION

This problem involves using trigonometry to find the height of a ladder against a wall.

Step 1: [Identify the Right Triangle]

The ladder, wall, and ground form a right triangle where the ladder is the hypotenuse, the wall height is the opposite side to the 60° angle, and the ground distance is the adjacent side.

\text{Ladder (hypotenuse)} = 10 \text{ m, Angle with ground} = 60°

Step 2: [Apply Sine Ratio]

Since we need the height (opposite side) and have the hypotenuse and angle, we use the sine function: sine of the angle equals opposite divided by hypotenuse.

\sin(60°) = \frac{\text{Height}}{10}

Step 3: [Calculate the Height]

Substitute the value of sin(60°) = √3/2 and solve for height.

\text{Height} = 10 \times \sin(60°) = 10 \times \frac{\sqrt{3}}{2} = \frac{10\sqrt{3}}{2} = 5\sqrt{3} \text{ m}

Step 4: [Convert to Decimal]

Calculate the approximate decimal value: 5√3 ≈ 5 × 1.732 = 8.66 m

The ladder reaches a height of 5√3 m or approximately 8.66 m on the wall.

Answer: (B) 5√3 m or 8.66 m

Test

Q.29 Medium Physics

A concave mirror has a focal length of 20 cm. An object is placed at 40 cm from the mirror. What type of image is formed?

A Virtual, erect, magnified

B Real, inverted, same size

C Virtual, erect, diminished

D Real, inverted, diminished

Correct Answer: B. Real, inverted, same size

EXPLANATION

Object at 2f (40 cm = 2 × 20 cm) forms image at 2f. Using mirror equation confirms v = 40 cm, m = -1 (real, inverted, same size as object).

Test

Q.30 Medium Physics

A wire of length L and cross-sectional area A has resistance R. If the wire is cut into two equal halves and connected in parallel, what is the new resistance?

A R/4

B R/2

C R

D 4R

Correct Answer: A. R/4

EXPLANATION

Each half has resistance R/2. When connected in parallel: 1/R_new = 1/(R/2) + 1/(R/2) = 4/R, so R_new = R/4.

Test

1 2 3 4 5 6

All Subjects & Topics

Govt. Exams

Entrance Exams

Teacher Exams

Subjects

Quick Links

General Science Physics

General Science
Physics