Physics Lecturer Past Paper 24-04-2024

Q11: Find the maximum value of resolving power of a grating 3 cm wide having 5000 lines per cm, if the wavelength of light used is 5890 A?

40000Å

45000Å

4500Å

5000Å

Q12: He____daily for a year now.

وہ ___ اب ایک سال سے روزانہ۔

Exercises

Was exercising

Has been exercising

Exercising

Q13: An electric field exerts a torque on a dipole only if?

برقی میدان صرف ایک ڈوپول پر ٹارک لگاتا ہے؟

The field is parallel to the dipole moment

The field is negative

The field is perpendicular to the dipole moment

The field is positive

Q14: Soap film exhibits brilliant colours in sun light due to?

صابن فلم کی وجہ سے سورج کی روشنی میں شاندار رنگوں کی نمائش؟

Dispersion of light

Interference of light

Diffraction of light

Scattering of light

Q15: How many fission take place per second in a 300 MW reactor, assuming each fission releases 200 MeV of energy?

2.38 x 10^18

9.38 x 10^18

4.38 x 10^18

8.38 x 10^18

Q16: A disc of mass 2 kg and diameter 2m is performing rotational motion. Find the work done, if the disc is rotating from 300 rpm to 600 rpm?

1479 J

14.79 J

147.9 J

1.479 J

Q17: The mean free path of nitrogen molecules at 27°C is 3 x 10^-7 m/s. If the average speed of nitrogen molecules at the same temperature is 600 m/s then the collision frequency will be?

10^-9/sec

1.5 x 10^-9/sec

2 x 10^-9/sec

3 x 10^-9/sec

Q18: When N-type semiconductor is heated?

جب این قسم کے سیمی کنڈکٹر کو گرم کیا جاتا ہے؟

Number of electrons increases while that of holes decreases

Number of holes increases while that of electrons decreases

Number of electrons and holes remain same

Number of electron and holes increases equally

Q19: Which of the following is not a postulate of Kinetic molecular theory of gases?

مندرجہ ذیل میں سے کون سا گیسوں کے کائنےٹک مالیکیولر تھیوری کا مرجع نہیں ہے؟

In gases there is a predominance of intermolecular energy

Collisions of gas molecules are elastic

All molecules have same speed at different temperatures

Do not exert the same pressure in all directions

Q20: The light of suitable frequency falling on metal surface ejects electrons, this phenomenon is called?

دھات کی سطح پر گرنے والی مناسب تعدد کی روشنی الیکٹرانوں کو خارج کرتی ہے، اس رجحان کو کہتے ہیں؟

X-ray emission

Compton effect

Nuclear fission

Photoelectric effect