Kpk Physics 2011 — Solved Past Paper with Answers

Q1. The force between two point charges placed in the air is F. If the air is replaced by a medium of relative permittivity εR. The force is reduced to ......

• A. εrF✓
• B. F/εr
• C. εr/F
• D. εr

Q2. The potential difference between two points A and B is ∆V. The work done w by the field in moving a charge ‘q’ from A to B is .......

• A. w=-q∆v✓
• B. w=q∆v
• C. w= - ∆v/q
• D. w= ∆v/q

Q3. N/C is the unit of ......

• A. energy✓
• B. potential difference
• C. electric intensity
• D. current

Q4. An ideal voltmeter is one which has ....... Resistance.

• A. zero✓
• B. finite
• C. infinite
• D. none

Q5. Joule’s law for heat dissipation in resistance R carrying current I is given by:

• A. W=I2R✓
• B. w=IRt
• C. w=IR2t
• D. w=I2R2t

Q6. Cyclotron frequency of an electron projected with velocity V perpendicular to the magnetic field β is given by.

• A. F = eβ/2xm✓
• B. eβ/2xe
• C. f = xe / βm
• D. f = 2π e/m β

Q7. The quantitative expression for motional emf is:

• A. B2Lv✓
• B. Lv/B
• C. BLv
• D. none

Q8. The unit of magnitude flux density is:

• A. weber/m2✓
• B. tesla
• C. NA-1m-1
• D. None of these

Q9. The energy stored in the field of an inductor of inductance L carrying current I is given by:

• A. 1/2LI2✓
• B. 1/2LI
• C. 1/2LI,
• D. LI

Q10. the resonance frequency of RLC series AC circuit is given by:

• A. fo = 2 π √1/LC✓
• B. fo = 1/2 π √1/LC
• C. fo = 1/2π √LC
• D. fo = 2 π LC

Q11. Tensile strain is:

• A. force/length✓
• B. stress / strain
• C. Change in length / original length
• D. strength x strain

Q12. 14x10'° pascal is the bulk modulus of

• A. steel✓
• B. copper
• C. aluminium
• D. iron

Q13. The light-emitting diode is ........ Biased

• A. reverse✓
• B. forward
• C. both A and B
• D. None

Q14. In order to create pair production, a photon must have energy.

• A. 0.511 Mev✓
• B. 1.02 Mev
• C. moc2
• D. Both B and C

Q15. According to the de-Broglie the wavelength associated with the particle moving with velocity v is:

• A. λ=hp✓
• B. λ=p/h
• C. λ=h/p
• D. Both A and B

Q16. The ionization energy of hydrogen atom is:

• A. 13.6 Mev✓
• B. 13 6 ev
• C. 1 36ev
• D. none

Q17. The ratio of the energies of electron of hydrogen atom in the first and second orbit it:

• A. 4✓
• B. 9
• C. 1/4
• D. 1/9

Q18. The range of β-particles in air is greater than that of α-particles by... times

• A. 10✓
• B. 100
• C. 1000
• D. 15