Faisalabad Board 2017
PHYSICS
Inter Part—2
Time Allowed: 3 Hours
Group 1               
Note:-Three are THREE sections in this paper i.e. Section A. B and C. Attempt Section-A on the same paper and return it to the superintendent within the given time. No marks will be awarded for Cutting, Erasing or Overwriting. Marks of Identification will lead to UFM case, Mobile Phone etc. are not allowed in the examination hall.

Q1. Write the correct option i.e. A, B, C or D in the empty, box provided opposite to each part.

• The product of resistance and capacitance is equal to:

1. Velocity
2. Force
3. Acceleration
4. Time

• NC^-1 is the SI unit of:

1. Force
2. Charge
3. Current
4. Electric Intensity

• Heat sensitive resistors are called:

1. Resistors
2. Capacitors
3. Thermistors
4. Inductors

• The sum of electric and magnetic force is called:

1. Maxwell force
2. Lorentz force
3. Newton's force
4. Centripetal force

• Shunt resistance is:

1. Low resistance
2. High resistance
3. Zero resistance
4. Impedance

• With the increase in speed of motor, the magnitude of back emf:

1. Remains same
2. Increase
3. Decreases
4. First increases then decreases

• A metal rod of 1m is moving at a speed of Ims-1 in a direction malting an angle  with 0.5T magnetic filed. The emf produced is:

1. 0.25N
2. 2.5N
3. 0.25V
4. 2.5V

• If 10 is the.peak value of an A.C. supply then its rms value will be given as Inns:

1. I_o/√2
2. √2I_o
3. I_o/2
4. 2I_o

• During each cycle, the alternate voltage reaches a peak value:

1. Once
2. Twice
3. Thrice
4. Four times

• In n-type vials, the minority carriers are:

1. Free electron
2. Holes
3. Protons
4. Mesons

• The Boolean expression of NAND gate is:

1. X = A.B
2. A - B
3. A + B
4. A + B

• Automatic function of streetlight can be done by the use of:

1. Inductor
2. Capacitor
3. Comparator
4. Thermistor

• If an object moves with speed of light, its mass will be:

1. Zero
2. Maximum
3. Minimum
4. Infinity

• In 1905, the special theory of relativity was proposed by:

1. Einstein
2. Bohr
3. Maxwell
4. De Broglie

• Balmer series lies in:

1. Infrared region
2. Visible region
3. Ultraviolet region
4. For ultraviolet region

• The charge on the B particle is:

1. +e
2. +2e
3. –e
4. None of these

• One joule of energy absorbed in a body per kg Is equal to:

1. 1rad
2. 1mm
3. 1Sievert
4. 1gray

SUBJECTIVE PART
SECTION B

Q2. Write short answers to any EIGHT (8) questions.

1. State Coulomb's law and write its formula.
2. Write two properties of electric field lines.
3. Electric lines of force never cross.Why?
4. Do electrons tend to go to region of high potential or of low potential?
5. Define Tesla and write its mathematical form.
6. State Ampere's law and write its formula.
7. How can you use a magnetic field to separate isotopes of chemical element?
8. Why the resistance of an ammeter should be very low?
9. Define motional emf and write its formula.
10. State Faraday's law of electromagnetic induction and write its formula.
11. Does the induced emf always act to decrease the magnetic flux through a circuit'?
12. Show that s and  have the same units.

Q3: Write short answers to any EIGHT (8) questions.

1. Why dues the resistance of a conductor rise with temperature?
2. Explain why the terminal potential difference of a battery decreases when the current drawn from it is increased'? State Ohms law. Express it mathematically.
3. Name the device that will
4. Permit the flow of D.C. but oppose the flow of A.C.
5. Permit the flow of A.C. but not D.C.
6. What is meant by A.M. and F.M.?
7. Define root mean square value of A.C. voltage.
8. Discuss the mechanism of electrical conduction by holes and electrons in a pure semi-conductor material.
9. What is meant by pars and diamagnetic substances?
10. What are super conductors?
11. The anode of a diode is 0.2v positive with respect-to cathode. Is it forward biased?
12. What is the principle of virtual ground? Write the gain of inverting amplifier.
13. What is the potential barrier of germanium and silicon? Also define potential barrier.
14. Why does the resistance of a conductor rise with temperature

Q4: Write short answers to any SIX question.

1. Why don't we observe a Compton Effect with visible light?
2. Will higher frequency light eject greater number of electrons than low frequency light?
3. If an electro and a proton have the same de Broglie wavelength, is hick particle has greater speed.
4. Can the electron in the ground state of hydrogen absorbs a photon of energy 13.6eV and greater than 13.6eV?
5. How does a x-rays differ from  x-rays?
6. What is radioactive tracer and give an example.
7. What do you understand by "background radiation"? Mention its sources.
8. Differentiate between Baryons and Mesons.
9. Define mass defect and binding energy.

SECTION-C

Note: Attempt any THREE questions.

Q5.

1. State Coulomb's law for electrostatic force. Discuss its vector form and show that F₁₂ = - F₁₂ 
2. A rectangular bar of iron is 2.0cm by 2.0cm in cross-section and 40cm long. Calculate its resistance if the resistivity of iron is 11x10^-8Ωm

Q6.

1. Derive the formula for energy stored in an inductor. Also define inductor.
2. A coil of 0.1m x 0.1m and of 200 turns carrying a current of 1.0 mA is placed in a uniform magnetic field of 0.1T. Calculate the maximum torque that acts on the coil.

Q7.

1. Explain A.C. through resistor in detail.
2. In a certain circuit, the transistor has a collector current of 10mA and a base current of 40. What is the current gain of transistor?

Q8.

1. What is the photoelectric effect? Derive the Einstein's photoelectric equation.
2. What stress would cause a wire to increase in kinath by 0.01% if the Young's modulus of the wire is 12x10¹⁰Pa what force would produce this stress if the diameter of wire is 0.56mm.

Q9.

1. What do you mean by inner shell transitions? Also explain the production of x-rays.
2. A sheet of lead 5.0mm thick reduces the intensity of a beam of y-rays by a factor 0.4. Find half value thick ness of lead sheet which will reduce the intensity to half of its initial value.