Class 6 Science – Chapter 9: Force and Machines – 40 Imp

Class 6 Science – Chapter 9: Force and Machines – 40 Impo

rtant MCQs for Junior Science Teacher Test

MCQs

Q1. What is force?
قوت کیا ہے؟

a) A push or pull
b) Mass of an object
c) Energy

Explanation: Force is any push or pull acting on an object.

Q2. Which instrument measures force?
قوت ناپنے کا آلہ کون سا ہے؟

a) Thermometer
b) Spring balance
c) Stopwatch

Explanation: Spring balance measures the magnitude of force applied.

Q3. Which of the following is an example of contact force?
مندرجہ ذیل میں سے کون سا رابطہ قوت کی مثال ہے؟

a) Friction
b) Gravity
c) Magnetism

Explanation: Friction occurs when surfaces are in contact.

Q4. Force can change:
قوت کیا تبدیل کر سکتی ہے؟

a) Speed of an object
b) Direction of motion
c) Both speed and direction

Explanation: Force can change both speed and direction of a moving object.

Q5. What is a simple machine?
سادہ مشین کیا ہے؟

a) A device to reduce work
b) A device to increase force
c) Both a and b

Explanation: Simple machines help reduce effort or increase force to do work.

Q6. Which of these is a lever?
مندرجہ ذیل میں سے کون سا لیور ہے؟

a) Seesaw
b) Pulley
c) Wheel

Explanation: A seesaw is an example of a lever that rotates around a fulcrum.

Q7. What is the fulcrum in a lever?
لیور میں محور کیا ہے؟

a) The pivot point
b) The load
c) The effort

Explanation: The fulcrum is the fixed pivot point about which a lever rotates.

Q8. First-class lever has:
پہلی کلاس کا لیور کس طرح ہوتا ہے؟

a) Fulcrum in the middle
b) Load in the middle
c) Effort in the middle

Explanation: In a first-class lever, fulcrum is placed between effort and load.

Q9. Which simple machine uses a wheel and a rope?
کون سی سادہ مشین پہیے اور رسی استعمال کرتی ہے؟

a) Pulley
b) Lever
c) Inclined plane

Explanation: Pulley uses a wheel and rope to lift or move loads.

Q10. Friction opposes:
رگڑ کس کے خلاف کام کرتی ہے؟

a) Motion
b) Force
c) Energy

Explanation: Friction always acts opposite to the direction of motion.

Q11. What is effort in a machine?
مشین میں کوشش کیا ہے؟

a) Force applied to do work
b) Weight of the machine
c) Distance moved

Explanation: Effort is the force applied to overcome the load using a machine.

Q12. Which machine increases the force?
کون سی مشین قوت بڑھاتی ہے؟

a) Pulley
b) Screw
c) Lever

Explanation: Levers and pulleys can increase the applied force.

Q13. Inclined plane helps by:
ترچھا سطح کس طرح مدد کرتی ہے؟

a) Reducing the effort
b) Increasing speed
c) Changing direction only

Explanation: Inclined plane reduces the effort needed to lift a load vertically.

Q14. Wedge is used to:
کیر (ویج) کا استعمال کس لیے ہوتا ہے؟

a) Cut objects
b) Lift loads
c) Rotate wheels

Explanation: Wedge is a simple machine used to cut or split objects.

Q15. Screw is a type of:
پیچ کس قسم کی مشین ہے؟

a) Lever
b) Inclined plane
c) Pulley

Explanation: Screw is an inclined plane wrapped around a cylinder.

Q16. Force has:
قوت کی خصوصیات کیا ہیں؟

a) Magnitude
b) Direction
c) Both magnitude and direction

Explanation: Force is a vector quantity having magnitude and direction.

Q17. What is load in a machine?
مشین میں بوجھ کیا ہے؟

a) Force applied
b) Object to be moved
c) Distance moved

Explanation: Load is the object that is lifted or moved using a machine.

Q18. Example of second-class lever is:
دوسری کلاس کا لیور کون سا ہے؟

a) Wheelbarrow
b) Seesaw
c) Scissors

Explanation: In second-class lever, load is between fulcrum and effort; e.g., wheelbarrow.

Q19. Example of third-class lever is:
تیسری کلاس کا لیور کون سا ہے؟

a) Tweezers
b) Wheelbarrow
c) Crowbar

Explanation: In third-class lever, effort is applied between load and fulcrum; e.g., tweezers.

Q20. Pulley helps to:
پلّی کس طرح مدد کرتی ہے؟

a) Change direction of force
b) Reduce effort
c) Both a and b

Explanation: Pulleys can lift heavy loads with less effort and change direction of force.

Q21. Friction can be reduced by:
رگڑ کو کس طرح کم کیا جا سکتا ہے؟

a) Lubrication
b) Heating
c) Cooling

Explanation: Lubricants like oil reduce friction between surfaces.

Q22. Which of these is not a simple machine?
مندرجہ ذیل میں سے کون سی سادہ مشین نہیں ہے؟

a) Lever
b) Pulley
c) Engine

Explanation: Engine is a complex machine, not simple.

Q23. Effort arm in lever is:
لیور میں کوشش کی لمبائی کیا ہے؟

a) Distance from fulcrum to effort
b) Distance from fulcrum to load
c) Distance moved by load

Explanation: Effort arm is the distance between fulcrum and point of effort application.

Q24. Load arm in lever is:
لیور میں بوجھ کی لمبائی کیا ہے؟

a) Distance from fulcrum to load
b) Distance from fulcrum to effort
c) Length of lever

Explanation: Load arm is the distance from fulcrum to the load.

Q25. What is mechanical advantage?
مشینی فائدہ کیا ہے؟

a) Ratio of load to effort
b) Ratio of effort to load
c) Speed of machine

Explanation: Mechanical advantage is the ratio of load lifted to effort applied.

Q26. Lever rotates around:
لیور کس کے گرد گھومتا ہے؟

a) Fulcrum
b) Load
c) Effort

Explanation: Lever rotates around the fixed pivot point called fulcrum.

Q27. Which machine is used to lift water?
پانی اٹھانے کے لیے کون سی مشین استعمال ہوتی ہے؟

a) Pulley
b) Lever
c) Wheel and axle

Explanation: Pulley system is used to lift water from wells.

Q28. Wheel and axle helps to:
پہیے اور محور کس طرح مدد کرتے ہیں؟

a) Move loads easily
b) Cut objects
c) Reduce force

Explanation: Wheel and axle reduces friction and makes moving objects easier.

Q29. Force is measured in:
قوت کس میں ناپی جاتی ہے؟

a) Newton
b) Joule
c) Watt

Explanation: Force is measured in Newton (N).

Q30. Lever helps to:
لیور کس طرح مدد کرتا ہے؟

a) Lift heavy objects
b) Reduce distance
c) Speed motion

Explanation: Lever allows heavy objects to be lifted with less effort.

Q31. Which type of pulley changes the direction of force only?
کون سی پلّی صرف قوت کی سمت بدلتی ہے؟

a) Fixed pulley
b) Movable pulley
c) Compound pulley

Explanation: Fixed pulley only changes the direction of applied force.

Q32. Movable pulley gives:
حرکت پذیر پلّی کیا فائدہ دیتی ہے؟

a) Mechanical advantage
b) Changes direction only
c) Reduces speed

Explanation: Movable pulley reduces effort and increases mechanical advantage.

Q33. Compound pulley combines:
مرکب پلّی کیا ملاتی ہے؟

a) Fixed and movable pulleys
b) Lever and screw
c) Wedge and wheel

Explanation: Compound pulley combines fixed and movable pulleys for more advantage.

Q34. Which is not an example of lever?
مندرجہ ذیل میں سے لیور کی مثال نہیں ہے؟

a) Scissors
b) Crowbar
c) Pulley

Explanation: Pulley is not a lever.

Q35. Ramp is an example of:
ڈھلوان کس کی مثال ہے؟

a) Inclined plane
b) Pulley
c) Lever

Explanation: Ramp is a simple inclined plane reducing effort to lift objects.

Q36. Lever is used to:
لیور کا استعمال کس لیے ہوتا ہے؟

a) Lift, push or pull
b) Cut objects
c) Increase weight

Explanation: Lever is used to lift, push, or pull loads with less effort.

Q37. Screw converts:
پیچ کیا تبدیل کرتا ہے؟

a) Rotational motion to linear motion
b) Linear motion to heat
c) Effort to speed

Explanation: Screw converts rotational force into linear motion for lifting or joining objects.

Q38. Wedge reduces:
کیر (ویج) کیا کم کرتا ہے؟

a) Effort
b) Distance
c) Motion

Explanation: Wedge reduces the effort required to cut or split objects.

Q39. Pulley system is used to:
پلّی سسٹم کس لیے استعمال ہوتا ہے؟

a) Lift heavy objects
b) Increase speed
c) Reduce weight

Explanation: Pulley system allows lifting heavy objects with less effort.

Q40. Machines help humans to:
مشینیں انسانوں کی کس طرح مدد کرتی ہیں؟

a) Do work easily
b) Make objects heavier
c) Increase distance

Explanation: Machines make work easier, faster, and less tiring for humans.

Answer Key

1. a
2. b
3. a
4. c
5. c
6. a
7. a
8. a
9. a
10. a
11. a
12. c
13. a
14. a
15. b
16. c
17. b
18. a
19. a
20. c
21. a
22. c
23. a
24. a
25. a
26. a
27. a
28. a
29. a
30. a
31. a
32. a
33. a
34. c
35. a
36. a
37. a
38. a
39. a
40. a