امتحان

The glass bulb made of -------

1

Mix fr om plastic a nd glass

2

Thin glass

3

Thick glass

تصحيح

The filament is made of tungsten because it has---------

1

High melting point

2

High boiling point

3

Low melting point

تصحيح

------prevents air fr om reaching the filament

1

Glass bulb

2

Copper wire

3

Lead wire

تصحيح

What was the main source of the light in old centuries?

1

the sun

2

Fire to r ches

3

Ca ndles

تصحيح

The most popular types of electric lamp are -------

1

Fluo r escent lamp

2

Light bulbs

3

Both a& b

تصحيح

--------increase the filament life time

1

Lead

2

Argon gas

3

Copper wires

تصحيح

who is the invento r of light bulbs

1

Thomas Edison

2

Isaac newton

3

Pythago r as

تصحيح

The effo r t arm equals 5 cm a nd the resistance arm equal 10 cm so -------

1

The effect fo r ce > the resistance fo r ce

2

The effect fo r ce = the resistance fo r ce

3

The effo r t fo r ce

تصحيح

Which of the following levers doesn’t save effo r t?

1

Nutcracker

2

Wheel barrow

3

Coal holder

تصحيح

In the ---------- class levers the fo r ce is smaller than resistance fo r ce

1

Second class levers

2

First class levers

3

Third class levers

تصحيح

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