Inter (Part-II) Multan Board 2015
Physics
Part II (Objective Type)
Time Allowed: 20 Minutes 
Max. Marks: 17

Note: You have four choices for each objective type question as A, B, C and D. The choice which you think is correct; fill that circle in front of that question number. Use marker or pen to fill the circles. Cutting or filling two or more circles will result in zero mark in that question.

Question #1
Circle the correct option i.e. A/B/C/D. Each part carries one mark.

• SI unit of Electric flux is:-

(A) Nmc⁻¹
(B) Nm⁻¹c⁻¹
(C) Nm²c⁻¹
(D) Nm³c⁻²

• The quantity ^∆V _∆r is called:-

(A) Electric potential
(B) Electric energy
(C) Potential barrier
(D) Potential gradient

• In Carbon resistors, the value of Blue Colour is:-

(A) 7
(B) 6
(C) 8
(D) 9

• (4) 1 Tesla =

(A) N⁻¹Am
(B) 1N Am²
(C) 1N A⁻¹m⁻²
(D) 1N A⁻¹m⁻¹

• Force on a charged particle is zero when projected at angle with the magnetic field.

  (A) 0^o
  (B) 90^o
  (C) 180^o
  (D) 270^o

• In case of inductor, energy is stored in the:-

  (A) Electric field
  (B) Magnetic field
  (C) Potential field
  (D) Gravitational field

• Commutator was invented by:-

  (A) Henry
  (B) Oersted
  (C) William Sturgeon
  (D) Maxwell 

• Main reason for worldwide use of A.C is:-

  (A) It is cheaper
  (B) Transmitted to long distance
  (C) Both A and B
  (D) Reaches in short time

• The combined effect of resistance and reactance is known as:-

  (A) Inductance
  (B) Conductance
  (C) Resistance
  (D) Impedance

• Young’s modulus for water is:-

(A) Zero
(B) 1
(C) 2
(D) 3

• Greater concentration of impurity is added in:-

  (A) Base
  (B) Emitter
  (C) Collector
  (D) LED

• The ratio β in transistor is called:-

  (A) Current gain
  (B) Voltage gain
  (C) Nuclear gain
  (D) Emitter gain

• Earth’s orbital speed is:-

  (A) 10 km/s
  (B) 20 km/s
  (C) 30 km/s
  (D) 40 km/s

• The value of Plank’s Constant h is:-

  (A) 63 × 10⁻³⁴ J.S
  (B) 6.63 × 10⁻³⁴ J / S
  (C) 6.63 × 10⁻³⁴ J.S²
  (D) 6.63 × 10⁻³⁴ J / S²

• Atom can reside in metastable state for:-

  (A) 10⁻¹sec
  (B) 10⁻² sec
  (C) 10⁻³ sec
  (D) 10⁻⁴ sec

• Half-life of Uranium–239 is:-

  (A) 5 minutes
  (B) 24.5 minutes
  (C) 25.5 minutes
  (D) 23.5 minutes

• Electrons are:-

  (A) Hadrons
  (B) Leptons
  (C) Quarks
  (D) Baryons 

Inter (Part-II) Multan Board 2015
Physics
Part II(Subjective)
Time Allowed: 2.10 Hours 
Max. Marks: 83 

Section I

2. Attempt any eight parts. 8 × 2 = 16

• Do electrons tend to go to the region of high potential or of low potential?
• Electric lines of force never cross, why?
• How can you identify that which plate of the capacitor is positively charged?
• Prove that RC has same unit as of time.
• Why the voltmeter should have very high resistance?
• What is Dead Beat Galvanometer?
• How can a current loop be used to determine the presence of a magnetic field in a given region of space?
• What is Lorentz Force?
• A suspended magnet is oscillating freely in a horizontal plane. The oscillations are strongly damped when a metal plate is placed under the magnet. Explain why this occurs?
• Can an electric motor be used to drive an electric generator with the output from the generator being used to operate the motor?
• What is back emf effect in motor?
• Define the Unit Henry.

3. Attempt any eight parts. 8 × 2 = 16

• Do bends in a wire affect its electrical resistance?
• What is Potentiometer? Write its two uses.
• What are the difficulties in testing whether the filament of a lighted bulb obeys Ohm’s Law?
• How many times per second will an incandescent lamp reach maximum brilliance when connected to a 50 Hz source? 
• How does doubling the frequency affect the reactance of (a) An inductor (b) A capacitor?
• What is “Choke”? Write its advantage over Rheostat.
• Define Superconductor. Write its two applications. 
• What is meant by Hysteresis loss? How is it used in the construction of a transformer?
• What are Paramagnetic and Ferromagnetic substances? Give one example of each. 
• Photo diode is operated in reverse biased state, Why?
• What is the net charge on an− type or a p− type substance?
• Write briefly abut Photo-Voltaic Cell.

4. Attempt any six parts. 6 × 2 = 12

• Which has the lower energy quanta? Radiowaves or X −
• Why don’t we observe a Compton effect with visible light?
• What is a Photocell? Write its at least two applications.
• How can the Spectrum of Hydrogen contain so many lines when Hydrogen contains one electron?
• What do we mean when we say that the atom is excited?
• What fraction of a radioactive sample decays after two half-lives have elapsed?
• Discuss the advantages and disadvantages of Nuclear Power, compared to the use of fossil fuel generated power.
• What are Isotopes? What do they have common and what are their differences?
• What is meant by Mass Defect and Binding Energy?

SECTION-II

NOTE: - Attempt any three questions.

Question #5.
(a) What is Wheatstone Bridge? Explain and prove the Principle of Wheatstone Bridge. How can it be used to find the unknown resistance of a wire? 5
(b) A point charge q=−8.0 × 10⁻⁸C is placed at the origin. Calculate electric field at a  point 2.0m from the origin on the z − axis. 3

Question #6.
(a) State Ampere’s Law and apply this law to find magnetic field due to a current  carrying Solenoid. 5
(b) The back emf in a motor is 120V when the motor is turning at 1680 rev. per min. What is the back emf when the motor turns 3360 rev. per min? 3

Question #7.
(a) Describe R – L – C series circuit and derive the relation for resonance frequency. 5
(b) A 1.25 cm diameter cylinder is subjected to a load of 2500 kg. Calculate the stress on the bar in mega Pascals. 3

Question #8.
(a) Briefly discuss “Transistor as an Amplifier”. Find its gain. 5
(b) An electron is placed in a box about the size of an atom that is about 1× 10⁻¹⁰m . What is the velocity of the electron? 3

Question #9.
(a) Define Laser. Explain construction, working principle of He − Ne Laser. 5
(b) The half-life of ₃₈⁹¹Sr is 9.70 hrs. Find its decay constant. 3