10th Class Physics MCQS Chapter 4

When frequency of sound wave is increased, which of the following decreases: i) Wavelength ii) Period iii) Amplitude

(i) And (iii) only

(i) Only

(i) And (ii) only

(iii) Only

Which is the most suitable means of reliable continuous communication between an orbiting satellite and earth:

Sound waves

Any light waves

Radio waves

Mecrowaves

Electric field lines:

cross each other in the region of weak field

always cross each other

never cross each other

cross each other inthe region of strong field

The speed of sound in air at 21 °C is:

336ms ¹

343ms^-1

430ms ¹

470ms ¹

The unit of electrical energy is:

Electron volt

Joule

Watt

Volt

The speed of sound in air at 100°C is:

380ms 1

300ms 1

386ms-1

382ms 1

SI unit of electric intensity is:

NC

NC ³

NC^-1

NC ²

Unlike charges always:

Sometimes repel and attract each other

Repel each other

Both A and B

Attract each other

A positive electric charge:

Repels a neutral particle

Attracts other positive charge

Repels other positive charge

Attracts a neutral particle

The pitch of a sound is most closely related to its:

Wave form

Frequency

Amplitude

Period