Physics MCQs

Question #1221

Share Report

The electric field inside a uniformly charged spherical shell is

A. Maximum at centre

B. Zero

C. Varies with distance

D. Uniform

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
Inside a spherical shell, field zero by Gauss's law.

This question belongs to: Science Physics

Question #1222

Share Report

The potential at a point due to a point charge is 10 V at distance 2 m. Potential at 4 m is

A. 2.5 V

B. 20 V

C. 10 V

D. 5 V

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
V ∝ 1/r. So if r doubled, V halved = 5 V.

This question belongs to: Science Physics

Question #1223

Share Report

The process of emission of electrons from a metal surface by heating is

A. Field emission

B. Photoelectric emission

C. Secondary emission

D. Thermionic emission

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
Thermionic emission: heat supplies energy to overcome work function.

This question belongs to: Science Physics

Question #1224

Share Report

In a transistor, the collector current is 1 mA and base current 10 μA. Emitter current is

A. 0.99 mA

B. 0.9 mA

C. 1.01 mA

D. 1.1 mA

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
I_E = I_C + I_B = 1 mA + 0.01 mA = 1.01 mA.

This question belongs to: Science Physics

Question #1225

Share Report

The decimal equivalent of binary number 1101 is

A. 9

B. 13

C. 15

D. 11

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
1×8 + 1×4 + 0×2 + 1×1 = 13.

This question belongs to: Science Physics

Question #1226

Share Report

A full wave rectifier uses

A. 1 diode

B. 4 diodes

C. No diodes

D. 2 diodes

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
Bridge rectifier uses 4 diodes. Centre-tap uses 2 diodes. Common full-wave uses 4.

This question belongs to: Science Physics

Question #1227

Share Report

The ripple factor of a full wave rectifier is approximately

A. 0.12

B. 0.01

C. 0.48

D. 1.21

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Full wave ripple factor ~0.48, half wave ~1.21.

This question belongs to: Science Physics

Question #1228

Share Report

The frequency of AC mains in India is 50 Hz. The time period is

A. 0.02 s

B. 50 s

C. 0.2 s

D. 0.5 s

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
T = 1/f = 1/50 = 0.02 s.

This question belongs to: Science Physics

Question #1229

Share Report

The power dissipated in a pure inductor in AC circuit is

A. Zero

B. VI

C. V²/R

D. I²R

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Phase difference 90°, power factor zero, average power zero.

This question belongs to: Science Physics

Question #1230

Share Report

The Q factor of a resonant LCR circuit is measure of

A. Reactance

B. Power factor

C. Impedance

D. Selectivity

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
Higher Q means sharper resonance, better selectivity.

This question belongs to: Science Physics

Question #1231

Share Report

The wavelength of visible light lies between

A. 1 mm - 10 mm

B. 700 nm - 1 mm

C. 400 nm - 700 nm

D. 1 nm - 10 nm

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Visible spectrum approx 400 nm (violet) to 700 nm (red).

This question belongs to: Science Physics

Question #1232

Share Report

A soap bubble appears coloured due to

A. Interference

B. Scattering

C. Dispersion

D. Diffraction

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
Thin film interference produces colours.

This question belongs to: Science Physics

Question #1233

Share Report

The phenomenon of bending of light around corners is called

A. Reflection

B. Refraction

C. Dispersion

D. Diffraction

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
Diffraction is bending around obstacles/apertures.

This question belongs to: Science Physics

Question #1234

Share Report

Polarization of light confirms that light is

A. Both

B. Longitudinal

C. Neither

D. Transverse

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option D

Explanation:
Only transverse waves can be polarized.

This question belongs to: Science Physics

Question #1235

Share Report

The velocity of light in vacuum is 3×10⁸ m/s. In a medium of refractive index 1.5, speed is

A. 4.5×10⁸ m/s

B. 3×10⁸ m/s

C. 2×10⁸ m/s

D. 1.5×10⁸ m/s

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
v = c/n = 3×10⁸/1.5 = 2×10⁸ m/s.

This question belongs to: Science Physics

Question #1236

Share Report

The power of accommodation of the eye is due to

A. Change in cornea

B. Change in curvature of lens

C. Change in retina

D. Change in pupil size

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option B

Explanation:
Ciliary muscles change lens shape, altering focal length.

This question belongs to: Science Physics

Question #1237

Share Report

A person with hypermetropia needs

A. Concave lens

B. Bifocal lens

C. Convex lens

D. Cylindrical lens

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Hypermetropia (farsightedness) corrected by converging convex lens.

This question belongs to: Science Physics

Question #1238

Share Report

The final image in an astronomical telescope is

A. Real and erect

B. Virtual and erect

C. Virtual and inverted

D. Real and inverted

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Telescope forms inverted, virtual image at infinity (or near point). For terrestrial, erecting lens makes erect.

This question belongs to: Science Physics

Question #1239

Share Report

The magnifying power of a simple microscope is maximum when the image is formed at

A. Near point

B. Focus

C. 2F

D. Infinity

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option A

Explanation:
M = 1 + D/f when image at near point (D = 25 cm). For infinity, M = D/f. So max at near point.

This question belongs to: Science Physics

Question #1240

Share Report

Which of the following is an example of a second order lever?

A. Scissors

B. Tweezers

C. Nutcracker

D. Fishing rod

View Answer & Solution Discuss

Get Complete Subject PDF for Science

Correct Answer: Option C

Explanation:
Load between fulcrum and effort: nutcracker, wheelbarrow. Scissors first order, fishing rod third.

This question belongs to: Science Physics

Practice Questions

More Science Topics