Name: PaperBanao
Price: 1000 PKR

Your school name

1st Year Physics First half Book Paper

1st Year · Physics · Punjab (PTB)

Name: ____________Roll No: ________Class/Section: ________Date: ________Total marks: 85Time: 3 hours

Q1. Multiple choice questions (Attempt all · 17 × 1 = 17)

If cross product of two vectors x points along positive z-axis, then the vectors and must lie in:
1. yz-plane
2. xz-plane
3. zy-plane
4. No plane
At constant temperature, the kinetic theory of gases leads to:
1. Boyle's law
2. Charles law
3. Avogadro's law
4. Joseph Lussat's law
Work has dimensions like:
1. Torque
2. Momentum
3. Velocity
4. Power
The quantity which remains constant in the equation of continuity is:
1. Volume
2. Mass flow rate
3. Pressure
4. Area
Which quantity of the following is dimensionless?
1. Angular velocity
2. Angular acceleration
3. Centripetal force
4. Angular displacement
Which of the following is a derived quantity?
1. Force
2. Mass
3. Length
4. Time
When an object is in free fall, what force is acting on it (Neglecting air resistance)?
1. Frictional force
2. Magnetic force
3. Gravitational force
4. Electric force
The Sl unit of product of pressure and volume is:
1. Watt
2. Joule
3. Pascal
4. Nm
A ball is thrown upward. As it rises, its:
1. K.E. increases, P.E. decreases
2. K.E. decreases, P.E. increases
3. Both K.E. and P.E. increases
4. Both K.E. and P.E. remain constant
The upthrust acting on a floating object is equal to:
1. Volume of the object
2. Density of the fluid
3. Weight of the object
4. Volume of water displaced
Centripetal force performs:
1. Maximum work
2. Minimum work
3. Negative work
4. No work
Which is the base quantity?
1. Area
2. Volume
3. Length
4. Density
The projectile gains its maximum height at an angle of:
1. 0^o
2. 45^o
3. 60^o
4. 90^o
The device which operates based on the second law of thermodynamics is:
1. Thermometer
2. Voltmeter
3. Barometer
4. Heat engine
The work done is said to be negative if:
1. Work is always positive
2. (eq) < 90^o
3. (eq) > 90^o
4. (eq) = 90^o
The lift force experienced by an aeroplane wings is primarily due to:
1. Viscosity of air
2. Density of air
3. Pressure difference above and below the wing
4. Gravitational force
In rotational motion, the torque is equal to rate of change of:
1. Angular velocity
2. Linear momentum
3. Angular Momentum
4. Angular acceleration

Q2. Short questions (Attempt any 8 of 12 · 8 × 2 = 16)

What is thrust?
Differentiate between dimensional and non-dimensional constant.
Can a vector have a component greater than the vector's magnitude?
How uncertainty can be reduced in a timing experiment?
Describe the circumstances for which velocity and acceleration of a vehicle are: (i) v is zero but a is not zero, (ii) a is zero but v is not zero. (iii) perpendicular to one another.
How many nano seconds in 1 year?
Which quantity remains same at all points on the trajectory of a projectile either velocity or acceleration? Explain.
Three students measured the length of a rod with a scale which minimum division is 1 mm and recorded as (i) 0.4235 m (ii) 0.42 m (iii) 0.424 m. Which record is correct and why?
What is the significance of resolving a vector into components?
Can dimensions help in deriving formulae?
Explain, what is meant by projectile motion? Derive expression for: (a) The time of flight (b)The range of projectile.
What is uncertainty in measurement?

Q3. Short questions (Attempt any 8 of 12 · 8 × 2 = 16)

Banked tracks are needed for turns on higway. why?
Is work done by a variable force always positive?
What is weightlessness?
A ball of mass m is held at a height h₁ above a table. The table top is at a height h₂ above the floor. One student says that the ball has potential energy mgh 1 but another says that it is mg (h₁+h₂). Whi is correct?
Mass is a measure of inertia in linear motion. What is its analogue in rotational motion? Describe briefly.
A body is being raised to a height H from surface of the Earth. What is the sign of work done by both (body and the Earth)? Justify.
What is the significant of moment of inertia?
What is non-conservative force? Give two examples.
What causes angular acceleration in a rotating object?
Point out positions where gravitational potential energy is takes as zero.
What causes a change in angular momentum?
A girl drop a cup from a certain height, which breaks into pieces. what energy changes are involved?

Q4. Short questions (Attempt any 6 of 9 · 6 × 2 = 12)

Does velocity remain constant along a streamline in steady flow?
Explain how thermodynamics applies to biological systems, such as human body.
How does pressure changes with depth in fluids?
A gas is expanding adiabatically. Explain what happens to temperature and pressure of the gas.
When pure water fall on a flat glass plate. It spread on the plate while mercury. when falls on the same plate gets converted into small globules. why?
Give two examples of adiabatic process.
A person is standing near a fast moving train, is there any danger that he will fall towards it?
Does kinetic theory apply to real gases at all conditions?
Explain how the swing is produced in a fast moving cricket ball?

Q5. Long questions (Attempt any 3 of 5 · 3 × 8 = 24)

Define first equation of motion by graphical method.
What are artificial satellites? Calculate the minimum time period necessary to put a satellite into the orbit near the surface of the Earth.
State the conventions for using Si units in detail.
A Carnot engine is operating between a high temperature reservoir at 600 k and a low temperature reservoir at 300 K. Calculate: (i) the maximum possible efficiency (ii) the amount of work output if the engine absorb 500 j of heat from the high temperature reservoir.
Justify that mass remains conserved when a fluid flows through a pipe.