Punjab Physics 2017 Paper 4 — Solved Past Paper with Answers

Q1. Question is given below:

• A. μoI✓
• B. μoA
• C. μoB
• D. None of the above

Explanation: The following is the solution:

Q2. If time constant in Re-circuit is small, the capacitor is charged or discharged:

• A. Rapidly
• B. At constant rate
• C. slowly
• D. intermediently✓

Explanation: Explanation will be added soon!

Q3. Power dissipated as heat in the conductor of resistor R due to electric current I is given by:

• A. I2R
• B. IR2
• C. I2Rt
• D. IRt✓

Explanation: Explanation will be added soon!

Q4. The electron gun in CRO consists of:

• A. Indirectly heated cathod
• B. Grid
• C. Three anodes
• D. all of these✓

Explanation: Explanation will be added soon!

Q5. Two parallel wires carring currents in the opposite direction:

• A. Repel each other
• B. Attract each other
• C. Have no effect upon each other
• D. They cancel out their individual magnetic field✓

Explanation: Explanation will be added soon!

Q6. When a coil is moved in a uniform magnetic field, an induced emf is produced due to change in:

• A. Flux density
• B. Electric flux
• C. magnetic flux
• D. magnetic field strength✓

Explanation: Explanation will be added soon!

Q7. The principle of an electric generator is based on:

• A. Biot-Savart's law
• B. Ampere's law
• C. Newton's law
• D. Faraday's law✓

Q8. Voltage across any two lines of a three phase A.C supply is:

• A. 220V✓
• B. 240V
• C. 300V
• D. 400V

Explanation: Explanation will be added soon!

Q9. The F.M transmission frequency range from:

• A. 50mHz to 175mHz
• B. 88mHz to 108mHz
• C. 120mHz to 240mHz
• D. 220mHz to 240mHz✓

Explanation: Explanation will be added soon!

Q10. The process in which magnetization reduced to zero by reversing the magnetizing current is called:

• A. Coercivity
• B. Hysteresis
• C. Retentivity
• D. Saturation✓

Explanation: Explanation will be added soon!

Q11. In a certain circuit, the transistor has a collector current 10mA and a base current of 4μA the current gain of the transistor will be:

• A. 125
• B. 200
• C. 250
• D. 300✓

Explanation: Explanation will be added soon!

Q12. Which of the followings are charge carriers inside a P-type crystal.

• A. positrons
• B. protons
• C. holes
• D. electrons✓

Explanation: Explanation will be added soon!

Q13. ‘The momentum of a photon of frequency f is:

• A. hc/f
• B. hf/c
• C. c/hf
• D. f/hc✓

Explanation: Explanation will be added soon!

Q14. Blue light has frequency 7.5x1014Hz. Its energy is:

• A. 9.3ev
• B. 6.2ev
• C. 5.6ev
• D. 3.1ev✓

Explanation: Explanation will be added soon!

Q15. Total energy of an electron in an orbit around the nucleus is sum of:

• A. Rotational and vibrational energy
• B. Vibrational and Kinetic energy
• C. Rotational and Kinetic energy
• D. Potential and Kinetic energy✓

Explanation: Explanation will be added soon!

Q16. One upquark and two down quarks makes a:

• A. Proton
• B. neutron
• C. meson
• D. Baryon✓

Explanation: Explanation will be added soon!

Q17. The most useful tracer is:

• A. Carbon-14
• B. Cobalt-60
• C. lodine-131
• D. Strontium-90✓

Explanation: Explanation will be added soon!