Kpk Physics 2010 — Solved Past Paper with Answers

Q1. An electron volt is the unit of:

• A. Potential
• B. Electric potential energy✓
• C. Charge
• D. Power

Explanation: Explanation will be added soon.

Q2. The resistance of a conductor depends on its:

• A. length✓
• B. area of cross section
• C. temperature
• D. all of these

Explanation: Explanation will be added later

Q3. The energy stored in a charged capacitor is given by:

• A. 1/2 C2 V2✓
• B. 1/2 V C2
• C. 1/2 Q V
• D. 1/2 Q v2

Explanation: Explanation will be added later

Q4. Joule’s law for heat dissipation in a resistor of resistance R carrying current is given by:

• A. W-IRt✓
• B. W=IR2t
• C. W=I2Rt
• D. W=I2R2I

Explanation: Explanation will be added later

Q5. The current I is flowing upward in the z-direction along a straight conductor. Its lines of magnetic filed are:

• A. parallel to the current✓
• B. anti parallel to the current
• C. clockwise around the conductor
• D. anti-clockwise around the conductor

Explanation: Explanation will be added later

Q6. Which one of the following does not affect the magnitude of the induced emf in electromagnetic induction through a coil?

• A. magnetic field✓
• B. resistance of coil
• C. speed of rotation of coil
• D. number of turns in coil

Explanation: Explanation will be added later

Q7. A galvanometer is converted into mili ammeter. The electrical resistance of the mili ammeter as compared with that of the galvanometer is:

• A. less✓
• B. more
• C. equal
• D. one half

Explanation: Explanation will be added later

Q8. A transformer is a device which works on the principle of:

• A. self inductance✓
• B. mutual inductance
• C. electromagnetic inductance
• D. motional emf

Explanation: Explanation will be added later

Q9. In which one of the following A.C circuits the power dissipation is maximum?

• A. RC senes circuit✓
• B. RL senes circuit
• C. RLC series circuit
• D. RLC series resonance circuit

Explanation: Explanation will be added later

Q10. Which one of the following material lacks the four properties of solid, strength, stiffness, ductility and toughness

• A. Steel✓
• B. putty
• C. zind
• D. rubber

Explanation: Explanation will be added later

Q11. A bar magnet can be demagnetized by:

• A. heating it✓
• B. striking with a hard object
• C. passing current through it
• D. All of these

Explanation: Explanation will be added later

Q12. The colorful light emitted by LED depends on:

• A. its forward bias✓
• B. its reverse bias
• C. the amount of forward current
• D. the type of semi conductor

Explanation: Explanation will be added later

Q13. The common emitter current amplification factor β given by:

• A. lc/1β✓
• B. lc/1e
• C. lE / lθ
• D. lB / lE

Explanation: Explanation will be added later

Q14. How many neutrons are there in the nuclide Zn66 ?

• A. 26✓
• B. 30
• C. 36
• D. 66

Explanation: Explanation will be added later

Q15. As the temperature of black body radiator is increased the wavelength of maximum intensity radiation will:

• A. Shift towards longer wavelength✓
• B. shift towards smaller wavelength
• C. unchanged
• D. can not be Predicted.

Explanation: Explanation will be added later

Q16. Light amplification by Stimulated emission of radiation means:

• A. X-Rays✓
• B. maser
• C. laser
• D. gamma rays

Explanation: Explanation will be added later

Q17. In Bohr’s model of H-atoms the radii of electron orbits are related to the quantum number n as:

• A. rnαn2✓
• B. rnαn2
• C. Vnα 1/n
• D. Vnα1/n2

Explanation: Explanation will be added later

Q18. The binding energy for nucleus A is 7.7 Mev and that for nucleus B is 7.8 Mev. Which nucleus has the larger mass?

• A. nucleus A✓
• B. nucleus B
• C. more information is needed
• D. None of these

Explanation: Explanation will be added later