Oglinzi Sferice și Lentile Subțiri

1.

În figura alăturată se observă o rază de lumină paralelă cu axa optică principală a unei lentile convergente, înainte de trecerea prin aceasta. F1 şi F2 sunt focarele lentilei. După trecerea prin lentilă, raza va urma traiectoria:

1

2

3

4

After passing through the converging lens, the parallel ray of light will converge and pass through the focal point on the opposite side of the lens. Therefore, the correct answer is 3.

Explanation

After passing through the converging lens, the parallel ray of light will converge and pass through the focal point on the opposite side of the lens. Therefore, the correct answer is 3.

2. Fenomenul de refracţie a luminii constă în:

Trecerea luminii într-un alt mediu, însoţită de schimbarea direcţiei de propagare

Suprapunerea a două unde luminoase

întoarcerea luminii în mediul din care provine la întâlnirea suprafeţei de separare cu un alt mediu

The phenomenon of light refraction refers to the passage of light from one medium to another, accompanied by a change in the direction of propagation.

Explanation

The phenomenon of light refraction refers to the passage of light from one medium to another, accompanied by a change in the direction of propagation.

3. Un obiect se află la distanţa de 60 cm în faţa unei lentile convergente cu distanţa focală de 20 cm. Ştiind că mărimea obiectului este 20 cm atunci distanţa de la imagine la lentilă și mărimea imaginii, vor fi:

1,5 cm și 0,5 cm

15 cm și 5 cm

15 cm și 0,5 cm

The correct answer is 15 cm și 5 cm. When an object is placed in front of a converging lens, the image formed is real, inverted, and magnified. The distance from the image to the lens is equal to the focal length of the lens, which in this case is 20 cm. The magnification of the image is given by the ratio of the image height to the object height, which is 5 cm / 20 cm = 0.25. Therefore, the image height is 0.25 times the object height, which is 0.25 * 20 cm = 5 cm.

Explanation

The correct answer is 15 cm și 5 cm. When an object is placed in front of a converging lens, the image formed is real, inverted, and magnified. The distance from the image to the lens is equal to the focal length of the lens, which in this case is 20 cm. The magnification of the image is given by the ratio of the image height to the object height, which is 5 cm / 20 cm = 0.25. Therefore, the image height is 0.25 times the object height, which is 0.25 * 20 cm = 5 cm.

4. Simbolurile mărimilor fizice fiind cele obişnuite în manualele de fizică, relaţia falsă referitoare la lentilelesubţiri este:

The symbols of physical quantities being the usual ones in physics manuals, the false statement regarding thin lenses is not available.

Explanation

The symbols of physical quantities being the usual ones in physics manuals, the false statement regarding thin lenses is not available.

5. Un obiect real este plasat în faţa unei lentile convergente. Distanţa dintre obiect şi lentilă este mai mare decât dublul distanţei focale a lentilei. Imaginea obiectului este:

Reală, mărită, răsturnată

Reală, micşorată, răsturnată

Virtuală, mărită, dreaptă

Virtuală, micşorată, dreaptă

When an object is placed in front of a converging lens at a distance greater than twice the focal length of the lens, the image formed is real, diminished (or smaller in size compared to the object), and inverted (or upside-down). This is because the rays of light from the object converge to form a real image on the opposite side of the lens. The image is smaller in size because the object is placed beyond the focal point of the lens, causing the rays to diverge before they reach the lens. The inverted nature of the image is a characteristic of converging lenses.

Explanation

When an object is placed in front of a converging lens at a distance greater than twice the focal length of the lens, the image formed is real, diminished (or smaller in size compared to the object), and inverted (or upside-down). This is because the rays of light from the object converge to form a real image on the opposite side of the lens. The image is smaller in size because the object is placed beyond the focal point of the lens, causing the rays to diverge before they reach the lens. The inverted nature of the image is a characteristic of converging lenses.

6. Imaginea unui obiect real printr-o lentilă divergentă poate fi numai:

Virtuală micşorată

Reală micşorată

Virtuală mărită

Reală mărită

When an object is viewed through a diverging lens, the image formed is always virtual and diminished in size. This means that the image is formed on the same side as the object and appears smaller than the actual object. The diverging lens causes the light rays to spread out, resulting in a virtual image that cannot be projected onto a screen. Therefore, the correct answer is "virtuală micşorată."

Explanation

When an object is viewed through a diverging lens, the image formed is always virtual and diminished in size. This means that the image is formed on the same side as the object and appears smaller than the actual object. The diverging lens causes the light rays to spread out, resulting in a virtual image that cannot be projected onto a screen. Therefore, the correct answer is "virtuală micşorată."

7. Convergența unei lentile este C= 5 δ. Distanța focală a lentilei este:

0,2 cm

2 cm

20 cm

The convergence of a lens is determined by its focal length. In this case, the given convergence value is 5 times the thickness of the lens, which means the lens has a focal length of 20 cm.

Explanation

The convergence of a lens is determined by its focal length. In this case, the given convergence value is 5 times the thickness of the lens, which means the lens has a focal length of 20 cm.

8. La trecerea luminii dintr-un mediu cu indice de refracţie

n subscript 1

într-un mediu cu indice de refracţie

n subscript 2

, între unghiul de incidenţă i şi unghiul de refracţie r există relaţia:

The explanation for the given correct answer is not available.

Explanation

The explanation for the given correct answer is not available.

9. O rază de lumină cade pe o suprafaţă perfect reflectătoare, sub unghiul de incidenţă

i equals 45 to the power of o

Se măreşte unghiul de incidenţă cu

15 to the power of o

Noul unghi format de raza incidentă cu raza reflectată are valoarea:

not-available-via-ai

Explanation

not-available-via-ai

10. Pentru a se obţine o imagine dreaptă şi mai mare decât obiectul, acesta trebuie plasat:

în faţa unei lentile convergente, între focarul obiect şi dublul distanţei focale

în faţa unei lentile divergente, între focarul imagine şi centrul optic al lentilei

în faţa unei lentile divergente, înaintea focarului imagine

în faţa unei lentile convergente, între focarul obiect şi centrul optic al lentilei

In order to obtain an upright and larger image than the object, it must be placed in front of a diverging lens, between the focal point of the image and the optical center of the lens.

Explanation

In order to obtain an upright and larger image than the object, it must be placed in front of a diverging lens, between the focal point of the image and the optical center of the lens.