Physics Questions Answers (MCQ) of General Intelligence listing is important for General Knowledge of SSC CGL, UPSC, IBPS, MAT, CAT and other competitive exams.

31) Two trains are running at 40 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast trai

• 1) \begin{aligned} 27\frac{7}{9} \end{aligned}
• 2) \begin{aligned} 28\frac{7}{9} \end{aligned}
• 3) \begin{aligned} 29\frac{7}{9} \end{aligned}
• 4) \begin{aligned} 30\frac{7}{9} \end{aligned}
Ans.   A
Explanation :
As Trains are moving in same direction, So, Relative Speed = 40-20 = 20 kmph = 20*(5/18) = 50/9 m/sec Length of Train= Speed * Time \begin{aligned} Length = \frac{50}{9}*5 \= \frac{250}{9} \=27\frac{7}{9} \end{aligned}

32) A train, 800 meter long is running with a speed of 78 km/hr. It crosses a tunnel in 1 minute. What is the length of the tunne

• 1) 650 meter
• 2) 555 meter
• 3) 500 meter
• 4) 458 meter
Ans.   C
Explanation :
Let length of tunnel is x meter Distance = 800+x meter Time = 1 minute = 60 seconds Speed = 78 km/hr = 78*5/18 m/s = 65/3 m/s Distance = Speed*Time \begin{aligned} => 800+x = \frac{65}{3}*60 \=> 800+x = 20*65 = 1300 \=> x = 1300 - 800 = 500 \\end{aligned} So the length of the tunnel is 500 meters. [If you want to calculate it practically, then please have your copy and pen and take a ride of Kalka to Shimla toy train in north India. It has many tunnels on the way :) ]

33) How many seconds will a 500 meter long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/

• 1) 25 Seconds
• 2) 28 Seconds
• 3) 30 Seconds
• 4) 35 Seconds
Ans.   C
Explanation :
Relative Speed = 63-3 = 60 Km/hr = 60 *(5/18) = 50/3 m/sec Time taken to pass the man will ne \begin{aligned} 500*\frac{3}{50} = 30 \text{ seconds} \end{aligned}

34) A jogger running at 9 kmph alongside a railway track is 240 metres ahead of the engine of a 120 metre long train running at 45 kmph in the same direction. In how much time will the train pass the jogger

• 1) 30 seconds
• 2) 32 seconds
• 3) 34 seconds
• 4) 36 seconds
Ans.   D
Explanation :
Speed of train relative to jogger = (45-9) = 36 kmph = 36*(5/18) = 10 m/sec Distance to cover = 240 + 120 = 360 metres Time = Distance/Speed So, \begin{align} Time = \frac{360}{10} = 36 \text{ Seconds} \end{align}

35) A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. Find the length of trai

• 1) 45 m
• 2) 50 m
• 3) 55 m
• 4) 60 m
Ans.   B
Explanation :
First person speed = 2*(5/18) = 5/9 m/sec Second person speed = 4*(5/18) = 10/9 m/sec Let the length of train is x metre and speed is y m/sec then, \begin{aligned} \frac{x}{y-\frac{5}{9}} = 9 \=> 9y-5 = x \=> 9y-x = 5 .....(i) \Also, \\frac{x}{y-\frac{10}{9}} = 10 \90y-9x = 100 .....(ii)\ \text{from (i) and (ii), we get,} \x=50 \end{aligned} So length of train is 50 metre

36) Which instrument is used to measure altitudes in aircraft's

• 1) Audiometer
• 2) Ammeter
• 3) Altimeter
• 4) Anemometer
Ans.   C
Explanation :
Ammeter - Measures strength of electric current. Audiometer - Measures intensity of sound. Anemometer - Measures force and velocity of wind and directions.

37) Which instrument is used to measure depth of ocean

• 1) Galvanometer
• 2) Fluxmeter
• 3) Endoscope
• 4) Fathometer
Ans.   D
Explanation :
Galvanometer - measures electric current, Fluxmeter - measures magnetic flux, Endoscope - used to examine internal parts of the body.

38) Name of the instrument to measure atomspheric pressure

• 1) Barometer
• 2) Barograph
• 3) Bolometer
• 4) Callipers
Ans.   A
Explanation :
Barograph - Recordings of atmospheric pressure, Bolometer - Used to measure heat radiation, Callipers - Used to measure inner and outer diameters of bodies.

39) Which instrument is used to measure the power of electric circuit

• 1) Voltmeter
• 2) Wattmeter
• 3) Wavemeter
• 4) Viscometer
Ans.   B
Explanation :
Voltmeter - is used to measure electric potential difference between two points, Wavemeter - is used to measure the wavelength of a radiowave, Viscometer - is used measure viscosity of liquid.

40) Which instrument is used in submarine to see the objects above sea level

• 1) Pykometer
• 2) Polygraph
• 3) Photometer
• 4) Periscope