Welcome to Physics Initial Test 4, an advanced online practice module designed specifically for candidates preparing for the initial academic tests of the Pakistan Armed Forces—including Pakistan Air Force (PAF) (GDP, CAE, Aeronautical Engineering, Airmen), Pak Army (Technical Cadet Course – TCC), and Pak Navy (PN Cadet, Operations, Engineering Branches).
Results
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#1. How many wave lengths of Kr^86 are contained in one meter?
#2. When two bodies stick together after collision, the collision is said to be
#3. A science student takes 100 observations in an experiment. Second time he takes 500 observations in the same experiment. By doing so the possible error becomes
#4. If the error in the measurement of radius of a sphere is 1% then the error in the measurement of volume will be
#5. Light year is the unit of
#6. Debye is the unit of
#7. The unit of surface energy per unit area may be expressed as
#8. A particle is projected horizontally from a height of 10m. Time taken by it to hit the ground is
#9. A force of 10N acts on a body of mass 2 kg for 2 sec. Rate of change of momentum of body is
#10. Sound waves having frequency in between 2KH and 4KH are called
#11. A body falling freely under the action of gravity has
#12. Keeping in view the Earth’s surface, the value of g on the equator is
#13. A uniform plank of weight 20 N is 200 cm long and rests on a support that is 60 cm from one end. At what distance from that end must an 80 N weight be placed in order to balance the plank?
#14. Multimode step index fibre has a core of relatively larger diameter such is
#15. Single mode step index fibre has a very thin core of about diameter
#16. How many phone calls can be carried by single mode step index fibre
#17. Multimode graded index fibre core has diameter of
#18. Optical fibres are of
#19. A body of mass 100 gm is suspended from a spring of force constant 50 N/m. The maximum acceleration produced in the spring is
#20. The time period of a second’s pendulum on the surface of moon is found to be 2√6. The acceleration due to gravity on the surface of moon is
#21. What will be the percentage change in the time period of a simple pendulum if its length is increased by 5%?
#22. Which of the following quantities is non-zero at the mean position for a particle executing SHM?
#23. The ratio of total energy of a harmonic oscillator to its average energy with respect to position will be
#24. If stress is increased beyond the elastic limit and change in solid is permanent, this behaviour is called
#25. To get P-type semiconductor we add impurity from
#26. 1st superconductor was discovered in year
#27. Triple point of water is
#28. Temperature of -273° C on Kelvin scale is
#29. In the isothermal process, one of the following is constant
#30. The concept of entropy was introduced by the scientist
#31. Carnot’s cycle is an example of
#32. Voltage gain for operational amplifier is maximum when used as
#33. The Boolean equation for NAND operation is written as
#34. In night switch op-amplifier is used as
#35. Which of the following does not obey Ohm’s law?
#36. A 5 ampere fuse wire can withstand a maximum power of 1 watt in the circuit. The resistance of the fuse wire is
#37. The Specific resistance of a wire
#38. The working of a dynamo is based on the principle of
#39. The magnitude of motional emf is given by
#40. What is SI unit of mutual inductance?
#41. A photosensitive metallic surface has work function hf_0. If photons of energy 2 hf_0 fall on this surface, the electrons come out with a maximum velocity 4×10^6 ms^-1. When the photon energy is increased to 5 hf_0 then maximum velocity is
#42. A laser used to weld detached retinas emits light with a wavelength 652 nm in pulses that are of 20 ms duration. The average power during each pulse is 0.6 W. Find the energy in each pulse in eV and in a single photon
#43. When the incident frequency is f_o, K is the (KE)_max of the electrons emitted and φ is work function of the surface. If incident frequency is doubled new (KE)_max will be
#44. A node voltage is at + 3V. Incident radiation has frequency 1.4×10^15 Hz and work function of the photoelectron cathode is 2.8 eV. Find the minimum and maximum KE of photon electron in eV
#45. In proton – proton cycle, number of protons consumed are
#46. One curie is equal to
#47. The mass density of a nucleus varies with mass number A as
#48. The energy released in a typical nuclear fusion reaction is approximately
#49. If a glass slab is placed in the path of a converging beam of light. The point of convergence of light
#50. The angle with the horizontal at which an underwater swimmer will see the setting sun is
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PHYSICS INITIAL TEST 4
Welcome to Physics Initial Test 4, an advanced online practice module designed specifically for candidates preparing for the initial academic tests of the Pakistan Armed Forces—including Pakistan Air Force (PAF) (GDP, CAE, Aeronautical Engineering, Airmen), Pak Army (Technical Cadet Course – TCC), and Pak Navy (PN Cadet, Operations, Engineering Branches). This practice quiz focuses on electromagnetic induction, alternating current (AC) circuits, electronics, and high-frequency multiple-choice questions needed to clear your computer-based military entrance exam with distinction.
Key Topics Covered in Physics Initial Test 4
To secure top marks in the Physics academic paper during your Armed Forces selection test, make sure to thoroughly revise these core physical concepts assessed in this module:
- Electromagnetic Induction: Faraday’s law, Lenz’s law, motional EMF, mutual and self-inductance, and transformer efficiency.
- Alternating Current (AC) Circuits: RMS values, phase relationships, impedance in RLC series circuits, resonance frequency, and power factor.
- Physics of Solids & Electronics: Elasticity, Young’s modulus, p-n junction diodes, rectification, operational amplifiers, and logic gates.
- Electromagnetic Waves: Maxwell’s predictions, speed of light equations, wave spectrum properties, and energy transport.
High-Frequency Sample MCQs for Practice
Test your understanding with these representative Physics MCQs frequently asked in tri-services academic tests:
1. Lenz’s Law of electromagnetic induction is a direct consequence of the law of conservation of:
A) Charge
B) Mass
C) Energy
D) Momentum
Answer: C) Energy
2. In an AC circuit containing only a pure inductor, the current:
A) Leads the voltage by 90°
B) Lags behind the voltage by 90°
C) Is in phase with the voltage
D) Lags behind the voltage by 180°
Answer: B) Lags behind the voltage by 90°
3. The root mean square (RMS) value of an alternating current with peak value $I_0$ is given by:
A) $I_0 / 2$
B) $I_0 / \sqrt{2}$
C) $\sqrt{2} I_0$
D) $2 I_0$
Answer: B) $I_0 / \sqrt{2}$
4. A step-up transformer increases which of the following quantities?
A) Power
B) Current
C) Voltage
D) Frequency
Answer: C) Voltage
5. The process of converting alternating current into direct current is called:
A) Amplification
B) Modulation
C) Rectification
D) Induction
Answer: C) Rectification
6. What is the output of an AND gate if both inputs are $1$?
A) $0$
B) $1$
C) High impedance
D) Undefined
Answer: B) $1$
7. The depletion region of a p-n junction diode consists of:
A) Free electrons only
B) Holes only
C) Immobile ions
D) Both free electrons and holes
Answer: C) Immobile ions
Detailed Overview of Physics Initial Test 4 Preparation
Preparing for Physics Initial Test 4 requires a clear understanding of inductive mechanisms, AC behavior, and semiconductor devices. In military selection centers, the computer-based Physics paper tests both basic electronics knowledge and electromagnetic field formulas under strict time constraints. Regular practice with structured question banks sharpens your ability to solve AC impedance problems, evaluate logic circuits, and ensure high accuracy during testing.
Effective Revision Tips for Test 4
- Master Phase Relationships: Remember that current lags voltage in inductors ($L$) and leads voltage in capacitors ($C$).
- Review Semiconductor Physics: Focus on forward and reverse bias characteristics of p-n junctions and diode rectifier configurations.
- Practice Timed Quizzes: Solve practice questions rapidly to build optimal time management skills under real testing conditions.
Useful Resources & Next Steps
- Next Quiz: Practice Physics Initial Test 5
- Main Hub: Access All Forces Academic Online Quizzes
- Official Websites:
Physics Academic Test Preparation: Circular Motion & Gravitation
Centripetal Acceleration, Kepler’s Laws & Universal Gravitation
Rotational kinematics, circular dynamics, and celestial mechanics form a fascinating and critical chapter of physics. Initial military screening tests frequently check candidate comprehension regarding centripetal force, angular velocity, banking of roads, Newton’s law of universal gravitation, orbital speed of satellites, and Kepler’s planetary laws. Grasping these concepts ensures you handle orbital and rotational queries with ease.
Centripetal force is not a new fundamental force of nature; rather, it is a role played by existing forces like tension, gravity, or friction pointing towards the center of a circular path.
Key Topics Covered in Physics Quiz 4
- Angular Displacement and Velocity: Relationship between linear speed ($v$) and angular speed ($\omega$) via $v = r\omega$. Angular acceleration and periodic time.
- Centripetal Force and Acceleration: Formula derivation and application ($a_c = \frac{v^2}{r} = r\omega^2$ and $F_c = \frac{mv^2}{r}$). Motion on banked roads and vertical loops.
- Newton’s Law of Universal Gravitation: Gravitational force equation ($F = G \frac{m_1 m_2}{r^2}$) and variation of acceleration due to gravity ($g$) with altitude and depth.
- Orbital Velocity and Escape Velocity: Formulas for satellite orbital velocity ($v_o = \sqrt{gr}$) and escape velocity from Earth ($v_e = \sqrt{2gr}$).
Crucial Orbital Formulas
- Centripetal Force: $F_c = \frac{mv^2}{r} = mr\omega^2$
- Orbital Speed: $v_o = \sqrt{g R}$
- Escape Velocity: $v_e = \sqrt{2g R} = \sqrt{2} v_o$
Proceed to Physics Quiz 4 below to check your problem-solving capability regarding gravitation and circular paths.