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Q1. The primary unit of speed in the SI system is:
The SI unit of speed is metre per second (m/s). Kilometre per hour is also a unit of speed but is not the SI unit. Metre per minute and centimetre per second are not standard SI units for speed. Metre per second is the correct SI unit.
Q2. If a cyclist covers 240 metre in 2 minute, the speed in metre per second is:
Speed = Distance/Time. Distance = 240 m, Time = 2 minutes = 2 × 60 = 120 seconds. Speed = 240/120 = 2 m/s. 120 m/s is distance per minute, 4 m/s is incorrect, and 480 m/s is distance × time. The correct answer is 2 m/s.
Q3. Which of the following is a renewable resource?
Solar energy is a renewable resource because it is continuously available and will not run out. Coal, natural gas, and oil are non-renewable fossil fuels that take millions of years to form and will eventually be exhausted. Solar energy is the correct answer.
Q4. A simple pendulum consists of a small metal ball called:
In a simple pendulum, the small metal ball suspended from a string or rod is called the bob. The string or rod holds the bob, the stand supports the setup, and the scale is not part of the pendulum. Bob is the correct term.
Q5. One complete to-and-fro motion of a pendulum bob is called:
One complete to-and-fro motion of a pendulum bob is called one oscillation. It is also called one vibration. One second is a unit of time, and one rotation is circular motion. Oscillation is the correct term.
Q6. The time taken by a pendulum to complete one oscillation is called:
The time taken by a pendulum to complete one oscillation is called its time period. Frequency is the number of oscillations per second, speed is distance per time, and wavelength is a wave property. Time period is the correct answer.
Q7. If a simple pendulum takes 40 second to complete 20 oscillations, its time period is:
Time period = Total time / Number of oscillations = 40 / 20 = 2 seconds. 0.5 seconds would be oscillations per second (frequency), 800 seconds is 40 × 20, and 20 seconds is the number of oscillations. The correct answer is 2 seconds.
Q8. The motion of a pendulum bob is an example of:
A pendulum bob moves back and forth in a regular pattern, which is oscillatory motion. Rectilinear motion is in a straight line, circular motion is in a circle, and random motion has no fixed path. Oscillatory motion is the correct answer.
Q9. Which of the following is NOT a unit of time?
Metre is a unit of length, not time. Second, hour, and minute are all units of time. The metre is used to measure distance or length, so it is NOT a unit of time. The correct answer is metre.
Q10. The speed of a moving object is defined as:
Speed is defined as the distance travelled per unit time. It is the rate at which an object covers distance. Time taken to cover a fixed distance is the inverse of speed, product is not a definition, and sum is incorrect. The correct definition is distance per unit time.
Q11. The symbol for second as a unit of time is written as:
The SI symbol for the second is ‘s’ (lowercase). ‘sec’ is an abbreviation, ‘se’ is not standard, and ‘S’ is used for siemens (unit of conductance). The correct symbol is ‘s’.
Q12. The symbol for metre as a unit of length is:
The SI symbol for metre is ‘m’ (lowercase). ‘mt’ is not standard, ‘M’ is mega (prefix), and ‘met’ is an abbreviation. The correct symbol is ‘m’.
Q13. The symbol for kilometre is:
The symbol for kilometre is ‘km’ (lowercase ‘k’ for kilo and ‘m’ for metre). ‘kM’ is incorrect, ‘Km’ is incorrect because ‘K’ is kelvin, and ‘k m’ has a space. The correct symbol is ‘km’.
Q14. Which device is used to measure time accurately in a laboratory?
A stopwatch is used to measure time accurately in a laboratory. Wall clocks are less precise, sundials are ancient, and hourglasses are not precise. A stopwatch can measure fractions of a second, making it suitable for accurate time measurement.
Q15. If a bus travels 360 kilometre in 6 hour, its speed in kilometre per hour is:
Speed = Distance/Time = 360 km / 6 h = 60 km/h. 2160 km/h is distance × time, 30 km/h is half, and 120 km/h is double. The correct speed is 60 km/h.
Q16. The time period of a simple pendulum depends on:
The time period of a simple pendulum depends on the length of the string and the acceleration due to gravity. It is independent of the mass, shape, or colour of the bob. The length of the string is the correct factor.
Q17. If the length of a simple pendulum is increased, its time period will:
The time period of a simple pendulum increases with the length of the string (T ∝ √L). If the length increases, the time period increases. Decreasing, remaining same, or becoming zero are incorrect. The correct answer is increase.
Q18. The number of oscillations completed in one second is called:
Frequency is the number of oscillations completed in one second. Time period is the time for one oscillation, amplitude is the maximum displacement, and speed is distance per time. Frequency is the correct term.
Q19. Which of the following is an oscillatory motion?
A swinging child on a swing moves back and forth in a regular pattern, which is oscillatory motion. A moving train is rectilinear, a rotating fan is circular, and a falling stone is rectilinear. A swinging child is the correct example of oscillatory motion.
Q20. A car moves with a speed of 15 metre per second. What is its speed in kilometre per hour?
To convert m/s to km/h, multiply by 18/5 (or 3.6). 15 × 18/5 = 54 km/h. 15 km/h is the same number but wrong unit, 4.16 km/h is dividing, and 150 km/h is multiplying by 10. The correct answer is 54 km/h.
Q21. The instrument that works on the principle of a pendulum to measure time is:
A pendulum clock works on the principle of a pendulum to measure time. Quartz clocks use quartz crystals, sand clocks use falling sand, and digital watches use electronic oscillators. A pendulum clock is the correct answer.
Q22. If an object moves along a straight line with constant speed, its motion is called:
Uniform motion is when an object moves along a straight line with constant speed (covering equal distances in equal time intervals). Non-uniform motion has changing speed, oscillatory is back-and-forth, and circular is in a circle. Uniform motion is the correct answer.
Q23. The odometer of a vehicle measures:
The odometer measures the total distance travelled by a vehicle. A speedometer measures speed, time is measured by a clock, and acceleration is not measured directly by these. Odometer measures distance.
Q24. A simple pendulum takes 32 second to complete 16 oscillations. Its time period is:
Time period = Total time / Number of oscillations = 32 / 16 = 2 seconds. 0.5 seconds is frequency, 512 is 32 × 16, and 48 is sum. The correct answer is 2 seconds.
Q25. Which of the following is the smallest unit of time among these?
Among hour, minute, second, and day, the second is the smallest unit of time. A minute is 60 seconds, an hour is 3600 seconds, and a day is 86,400 seconds. The second is the smallest.
Q26. The motion of a bouncing ball is an example of:
A bouncing ball moves up and down in a repeated pattern, which is oscillatory motion. It is not purely rectilinear or circular, and it is definitely moving. Oscillatory motion is the correct classification.
Q27. The speed of a moving object is said to be non-uniform if:
Non-uniform speed means the object covers unequal distances in equal intervals of time. Uniform speed means equal distances in equal time. Not moving means zero speed, and moving in a circle can be uniform or non-uniform. Non-uniform speed is when distances are unequal.
Q28. One hour is equal to:
One hour = 60 minutes = 60 × 60 seconds = 3600 seconds. 60 seconds is one minute, 100 seconds is not correct, and 24 seconds is not correct. The correct answer is 3600 seconds.
Q29. In a simple pendulum, the fixed point from which the bob hangs is called:
The fixed point from which the bob hangs is called the support. The mean position is the lowest point, the extreme position is the highest point, and the pivot is a similar term but less commonly used for a simple pendulum. Support is the correct term.
Q30. If a train travels 600 metre in 30 second, its speed is:
Speed = Distance/Time = 600 m / 30 s = 20 m/s. 18000 m/s is 600 × 30, 0.05 m/s is 30/600, and 630 m/s is sum. The correct answer is 20 m/s.
Q31. The time period of a pendulum is measured in:
Time period is the time taken for one oscillation, so it is measured in seconds. Metre is a unit of length, metre per second is speed, and hertz is frequency. The correct unit is second.
Q32. Which of these clocks is based on the principle of a simple pendulum?
A pendulum wall clock is based on the principle of a simple pendulum. Atomic clocks use atomic vibrations, quartz clocks use quartz crystals, and digital clocks use electronic oscillators. A pendulum wall clock is the correct answer.
Q33. A car travels 90 kilometre in 1.5 hour. Its average speed is:
Speed = Distance/Time = 90 km / 1.5 h = 60 km/h. 135 km/h is 90 × 1.5, 90 km/h is the distance, and 45 km/h is half. The correct speed is 60 km/h.
Q34. The mean position of a pendulum is:
The mean position of a pendulum is the lowest point of its swing, where it hangs vertically. The highest points are the extreme positions, and the point of suspension is the support. The lowest point is the mean position.
Q35. If a pendulum takes 5 second for one oscillation, its time period is:
The time period is the time taken for one oscillation. If it takes 5 seconds for one oscillation, the time period is 5 seconds. 0.2 seconds is frequency, 10 seconds is two oscillations, and 2.5 seconds is half. The correct answer is 5 seconds.
Q36. The unit kilometre per hour is used to express:
Kilometre per hour (km/h) is a unit of speed, expressing distance travelled per hour. Time is measured in hours, distance in kilometres, and oscillation is a motion. The correct answer is speed.
Q37. A simple pendulum is taken to the Moon. Its time period will:
The time period of a pendulum is inversely proportional to the square root of gravity (T ∝ 1/√g). Since the Moon’s gravity is about 1/6 of Earth’s, the time period will increase. Decrease, remain same, and become zero are incorrect. The correct answer is increase.
Q38. The motion of a child on a sea-saw is:
A child on a sea-saw moves up and down in a regular, repeated pattern, which is oscillatory motion. Circular motion is rotation, translatory is straight-line, and random motion is irregular. Oscillatory motion is the correct answer.
Q39. Convert 72 kilometre per hour into metre per second.
To convert km/h to m/s, multiply by 5/18 (or divide by 3.6). 72 × 5/18 = 20 m/s. 259.2 m/s is 72 × 3.6, 72 m/s is the same number, and 0.02 is dividing by 3600. The correct answer is 20 m/s.
Q40. Which of the following is NOT a unit of speed?
m/s, km/h, and cm/s are all units of speed. s/m (seconds per metre) is the inverse of speed and is not a standard unit of speed. The correct answer is s/m.
Q41. The time taken by a pendulum to complete one oscillation is called its:
The time taken for one complete oscillation is the time period. Frequency is the number of oscillations per second, amplitude is maximum displacement, and length is the string length. Time period is the correct answer.
Q42. A man walks 500 metre in 250 second. His speed is:
Speed = Distance/Time = 500 m / 250 s = 2 m/s. 0.5 m/s is 250/500, 125000 m/s is 500 × 250, and 750 m/s is sum. The correct answer is 2 m/s.
Q43. The maximum displacement of a pendulum bob from its mean position is called:
Amplitude is the maximum displacement of the bob from its mean position. Time period is the time for one oscillation, frequency is oscillations per second, and oscillation is one complete to-and-fro motion. Amplitude is the correct term.
Q44. Which of these motions repeats itself after a fixed interval of time?
Periodic motion repeats itself after a fixed interval of time. Random motion does not repeat, linear motion is along a straight line, and circular motion repeats but is a type of periodic motion. Periodic motion is the general term for repeating motion.
Q45. A bus moves with a speed of 30 metre per second. How much distance will it cover in 10 second?
Distance = Speed × Time = 30 m/s × 10 s = 300 m. 3 m is 30/10, 40 m is sum, and 20 m is difference. The correct answer is 300 m.
Q46. The symbol for hour as a unit of time is:
The symbol for hour is ‘h’ (lowercase). ‘hr’ is an abbreviation, ‘H’ is the symbol for henry (unit of inductance), and ‘ho’ is not standard. The correct symbol is ‘h’.
Q47. Which of the following is an example of uniform motion?
Uniform motion is when an object moves at a constant speed. A fan running at constant speed is uniform motion. A car speeding up, a train slowing down, and a ball falling are all examples of non-uniform motion (changing speed). A fan at constant speed is the correct answer.
Q48. If a pendulum has a time period of 1.5 second, the number of oscillations it completes in 30 second is:
Number of oscillations = Total time / Time period = 30 s / 1.5 s = 20 oscillations. 45 is 30 × 1.5, 30 is total time, and 15 is half. The correct answer is 20.
Q49. Which of the following is the correct symbol for metre per second?
The correct symbol for metre per second is ‘m/s’. ‘mps’ is an abbreviation, ‘m.s’ is not standard, and ‘m-s’ is incorrect. The correct SI symbol is m/s.
Q50. To measure the time period of a pendulum accurately, we should:
To measure the time period accurately, we measure the time for a larger number of oscillations (say 20) and then divide by the number of oscillations. This reduces the error caused by reaction time. Measuring one oscillation is less accurate, multiplying by 100 is incorrect, and guessing is not accurate. The correct method is to measure multiple oscillations and divide.