Measurement & Units:
Railway Board offers opulent and revered job posts to its aspirants. And it is not every year that we get the notification from Railway offering a good number of vacant seats to the multitude aspirants. But the current year 2018 brought a pleasant surprise with almost 90,000 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy. The exam will be conducted in the months of May 2018.
Q1. The unit of power is-
शक्ति की इकाई है-
(a) Hertz / हेटर्स
(b) Volts / वोल्ट
(c) Watt / वाट
(d) Neutrons/ न्यूट्रॉन
Sol. In the field of Physics watt is measurement of power, describing the rate at which electricity is being used at a specific moment.
Power = Work/Time
The S.I. unit of power is watt, which is equal to joule per second.
Q2. The unit of the force is-
बल की इकाई क्या है-
(a) Faraday / फैराडे
(b) Fermi / फर्मी
(c) Newton / न्यूटन
(d) Rutherford / रदरफोर्ड
Sol. The S.I. unit of Force is ‘Newton’ or Kg. m/sec2.
Force = mass × acceleration
The net force on an object is product of object mass and acceleration generated.
Q3. The unit of work is:
कार्य की इकाई क्या है:
(a) Joule /जूल
(b) Neutron / न्यूट्रॉन
(c) Watt / वाट
(d) Dyne /डायन
Sol. When a force acts to move an object, then work done by the force is equivalent to the product of force and displacement in the direction of force. It is a scalar quantity. The S.I unit of work is Newton metre, which is also called as Joule. Joule is also the unit of Energy.
Q4. The SI unit of electrical resistivity of conductor is-
कंडक्टर की विद्युत प्रतिरोधकता की एसआई इकाई है-
(a) Faraday / फैराडे
(b) Volts / वोल्ट
(c) Ampere / एम्पेयर
(d) Ohm-metre (Ω⋅m). / ओहम मीटर (Ω⋅m)
Sol. The SI unit of electrical resistivity is the ohm-metre (Ω-m).
Q5. Light year is the unit of-
प्रकाश वर्ष किसकी इकाई है
(a) Distance / दूरी
(b) Time /समय
(c) Speed of light / प्रकाश कि गति
(d) Intensity of light / प्रकाश की तीव्रता
Sol. Light year is a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.46 × 1015 metres.
Q6. A parsec, a unit of distance used to measure the distance related to the stars in the sky, is equal to-
एक पारसेक, आकाश में सितारों से संबंधित दूरी को मापने के लिए दूरी की एक इकाई है, यह किसके बराबर है-
(a) 4.25 light-years / प्रकाश वर्ष
(b) 3.26 light-years / प्रकाश वर्ष
(c) 4.50 light-years / प्रकाश वर्ष
(d) 3.05 light-years / प्रकाश वर्ष
Sol. A PARSEC is a unit of length used to measure the astronomically large distance of objects outside the solar system.
1 PARSEC = 3x 1016 Metres
1 Light year = 9.46 x 1015 Metres
So, 1 PARSEC = 3.262 light years.
Q7. PARSEC is the unit of:
PARSEC किसकी इकाई है
(a) Distance / दूरी
(b) Time /समय
(c) Light intensity / प्रकाश की तीव्रता
(d) Magnetic force / चुंबकीय बल
Sol. A PARSEC is a unit of length used to measure the astronomically large distance of objects outside the solar system.
One parsec is equal to about 3.26 light-years (30 trillion km or 19 trillion miles) in length.
Q8. Which unit of measurement is multiplied by 0.39 to convert it to ‘inches’?
किस मापन इकाई को ‘इंच’ में परिवर्तित करने के लिए 0.3 इंच से गुणा किया जाता है?
(a) Millimetre / मिलीमीटर
(b) Centimetre / सेंटीमीटर
(c) Metre / मीटर
(d) Decimetre /डेसीमीटर
Sol. 1 Centimetre = 0.39 inch, so we can multiply centimeter by 0.39 to convert it to inches’.
Q9. How can the height of a person who is six feet tall, be expressed (approximately) in nanometer?
छह फीट लंबे व्यक्ति की ऊंचाई, नैनोमीटर में (लगभग) किस रूप में व्यक्त की जा सकती है?
(a) 183× 10^6nm
(b) 234× 10^6nm
(c) 183× 10^7nm
(d) 181× 10^7nm
Sol. 1 nonaometre = 10-9 metre
1 Feet = 0.305 metre
1 Feet = 30.5 × 107 nanometre
6 Feet = 6 × 30.5 × 107 nanometre
= 183 × 107 nanometre
Q10. A nanometer is equal to-
एक नैनोमीटर किसके बराबर है-
(a) 10^(-6) cm
(b) 10^(-7) cm
(c) 10^(-8) cm
(d) 10^(-9) cm
Sol. A nanometer is equal to- 10-7) cm
Q11. Ampere is the unit of-
एम्पियर किसकी इकाई है
(a) Voltage / विद्युत दाब
(b) Electric current / विद्युत प्रवाह
(c) Resistance / प्रतिरोध
(d) Power / शक्ति
Sol. Ampere is a unit to measure electric current. If one Ampere current is flowing in any conducting wire, it means 6.25 × 10-18 electrons are entering per second from one direction and same amount of electrons flows from the other end per second.
Q12. Megawatt is the measuring unit of power which is-
मेगावाट उस शक्ति की मापक इकाई है जो-
(a) Generated /उत्पन्न की गयी है
(b) Consumed / खपत की गयी है
(c) Saved /बचत की गयी है
(d) Lost in transmission / संचरण में हानि हुई है
Sol. Megawatt is the measuring unit of power, which is generated in electricity generation plants. 1 Megawatt is equal to 106 (million) watt.
List-I List-II
(Physical quantities) (Units)
A. Acceleration 1. Joule
B. Force 2. Newton second
C. Work done 3. Newton
D. Impulse 4. Metre/second2
Code: ABCD
(a) 1 234
(b) 3412
(c) 2 341
(d) 4312
Sol. Acceleration is the rate of change of velocity of an object. The S.I. unit of acceleration is the metre per second square (m/s2). The S.I. unit of force is Newton (N). The S.I. unit of Impulse is the Newton Second (N.S). The S.I. unit of Work is Joule.
Q14. Match List-I with List-II and select the correct answer using codes given below:
List-I List-II
(Units) (Parametric quantities)
A. Watt 1. Heat
B. Knot 2. Navigation
C. Nautical mile 3. Speed of a ship
D. Calorie 4. Power
Code: ABCD
(a) 3 142
(b) 1234
(c) 4 321
(d) 2413
Sol. The SI unit of power is the Watt (w), which is equal to one joule per second. Knot is the unit of measuring of speed of a ship. Nautical mile is a unit of distance used by navigators in sea. Calorie is a unit of measuring heat and energy.
Q15. How many watts are there in a horsepower?
एक हौर्सपॉवर में कितने वाट हैं?
(a) 1000
(b) 750
(c) 746
(d) 748
Sol. Horse power is a unit of measurement of power (the rate at which work is done).
1 Watt = 1 Joule/second
1 Horse power = 746 watt.
You may also like to read:
