Inter (Part-II) Sahiwal Board 2016
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.

• At high frequency the value of reactance of capacitor will be:

(a) Small
(b) Zero
(c) Large
(d) Infinite

• The basic circuit element in a D.0 circuit which controls the current and voltage is:

(a) Capacitor
(b) Resistor
(c) Inductor
(d) Transistor

• Good conductors have conductivities of the order of:

(a) 103(Ωm)-1
(b) 105 (Ωm)-1
(c) 107 (Ωm)-1
(d) 109 (Ωm)-1

• The colour of light emitted by a LED depends on:

(a) Its forward biasing
(b) The type of semi conductor material used
(c)The amount of forward current
(d) Its reverse biasing

• The potential barrier for germanium at room temperature is:

(a) 0.3 Volts
(b) 0.5 Volts
(c) 0.7 Volts
(d) 0.9 Volts

• Rest mass of photon is:

(a) 1.67 x 10'7 kg
(b) 9.1 x 10-31 kg
(c) Infinite
(d) Zero

• When platinum wire is heated, it changes to cherry red at temperature:

(a) 500°C
(b) 900°C
(c) 1100°C
(d) 1300°C

• Helium - Neon laser discharge tube contains neon:

(a)15%
(b)25%
(c)82%
(d) 85%

• The SI unit of magnetic induction is:

(a) Weber
(b) Tesla
(c) Newton
(d) Weber per meter

• Lenz's Law is in accordance with law of conservation of:

(a) Mass
(b) Momentum
(c) Charge
(d) Energy

• 1 a.m.0 is equal to:

(a)1.66 x 10^-9 kg
(b)1.66 x 10^-24 kg
(c)1.66 x 10^-7 kg
(d)1.66 x 10^-34 kg

• Thyroid cancer is cured by:

(a)Iodine – 131
(b)Carbon – 14
(c)Sodium – 24
(d)Cesium – 137

• The electron volt is the unit of:

(a)Electric current
(b)Electric energy
(c)Potential
(d)Potential difference

• For computation of electric flux, the surface area should be:

(a) Parallel
(b) Curved
(c) Spherical
(d) Flat

• If fourth band is missing on resistance, its tolerance is:

(a) ±5%
(b) ±10%
(c) ±15%
(d) ±20%

• The sensitivity of galvanometer is given by:

(a) C/BAN
(b) BAN/C
(c) CAN/B
(d) B/CAN

• The motional emf is given by:

(a) qvB
(b) iBL
(c) eBL
(d)vBL

Inter (Part-II) Sahiwal Board 2016
Physics
Part II (Subjective)
Time Allowed: 3.10 Hours 
Max. Marks: 83

Section I

2. Attempt any EIGHT short questions. (8 x 2 = 16)

• Suppose that you follow an electric field line due to a positive point charge. Do electric field and the potential increase or decrease? Explain briefly.
• Describe the force or forces on a positive point charge when placed between parallel plates with opposite and equal charges.
• Define potential gradient. Give its unit.
• Electric lines of force never cross each other. Why?
• Describe the change in magnetic field inside a solenoid carrying a steady current if the number of turns is doubled but the length remains same.
• Suppose that a charge "q" is moving in a uniform magnetic field with velocity II v It Why is there no work done by the magnetic force that acts on charge "q"?
• What is current sensitivity of a galvanometer?
• Why the resistance of an ammeter should be very low?
• In a certain region, the earth's magnetic field point vertically down. When a plane flies due north, which wingtip is positively charged?
• Four unmarked wires emerge from a transformer. What steps would you take to determine turn ratio.
• What is back motor effect in generators?
• Why transformers are used in the A.C supply network?

3. Attempt any EIGHT short questions. (8 x 2 = 16)

• Do bends in a wire affect its electrical resistance? Explain.
• What are the difficulties in testing whether the filament of a lighted bulb obeys Ohm's law?
• Find out equivalent resistance when resistances are connected in series and in parallel.
• What is meant by A.M and F.M?
• How the reception of a particular radio station is selected on your radio set?
• How does doubling the frequency affect the reactance of (a) an inductor (b) a capacitor?
• What are superconductors? Give one name of any superconductor.
• Show that the units of modulus of elasticity and stress are same.
• What are the two main differences between conductors and semi conductors?
• Why a photodiode is operated in reverse biased state?
• The anode of a diode is 0.2 V positive with respect to its cathode. Is it forwad biased?
• What is photodiode? Write down its any two applications.

4. Attempt any SIX short questions. (6 x 2 = 12)

• Explain NAVSTAR navigation system.
• Can pair production take place in vacuum? Explain.
• If an electron and a proton have the same de-Broglie wave length, which particle has greater speed?
• Write down two uses of LASER in industry.
• State any two postulates of Bohr's atomic model.
• What are isotopes? What do they have in common and what are their differences?
• What fraction of a radioactive sample decays after two half – lives elapsed?
• Define mass of defect and binding energy.
• Enlist the basic forces of nature.

SECTION –II

Attempt any THREE questions:

Question #5
(a) Define capacitor and capacitance. Find an expression for the capacitance of a parallel plate capacitor when a dielectric material is inserted between the plates.
(b) The potential difference between the terminals of a battery in open circuit is 2.2 V. When it is connected across a resistance of 5.0 S2 , the potential falls to 1.8 V. Calculate the current and the internal resistance of the battery.

Question #6
(a) Derive an expression for energy stored in an inductor in terms of magnetic field.
(b) What current should pass through a solenoid that is 0.5m long with 10,000 turns of copper wire so that it will have a magnetic field of 0.4 T?

Question #7
(a) Explain the principle of generation transmission and reception of electromagnetic waves.
(b) A wire 2.5 m long and cross section area 10-5m2 is streteched 1.5 mm by a force of 100 N in the elastic region. Calculate Young's modulus.

Question #8
(a) What are logic gates. Discuss the OR Gate and AND Gate.
(b) Find the mass m of a moving object with speed 0.8 c.

Question #9
(a) Give the postulates of Bohr's model of the Hydrogen atom and how de-Broglie justify IInd postulate on basis of modern physics.
(b) The half-life of 38 Sr" is 9.70 hours. Find its decay constant.

SECTION- III

Question #10
(A) Give answer to any four parts.

• State Ohm's law and give its mathematical form.
• What is meant by dead beat galvanometer? Explain briefly.
• Why the resistance of voltmeter should be high? Explain briefly.
• Define potentiometer and its principle.
• Define electric current and potential difference.
• Define intensity of light and give its SI unit.
• Differentiate between depletion region and potential barrier.
• What is capacitor? Define capacitances.

(B) Write down the brief procedure to find the internal resistance of a cell using a potentiometer.
OR
Write down the procedure to study the relation between current and capacitance when different capacitors are used in A.0 circuit.

(C) Answer the question given below on the basis of following graph:

• Find the slope of the graph A.
• What do you infer from the graph A?

Graph - A

(Graph)

OR

• Find the slope of the I-V graph B
• What do you infer from the I- V graph B.