Physics [Unit & Dimensions] Questions for Railway ALP Stage-II Exam : 27th November 2018

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 1,27,278 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy. 



Q1. Which of the following is not a vector quantity?
इनमें से कौन एक उक्त रेखा (वेक्टर क्वांटिटी) नहीं है?
(a) Speed / गति
(b) Velocity / वेग
(c) Torque / टार्क 
(d) Displacement / विस्थापन
Show Answer
Ans.(a)
Sol. A vector quantity has a direction and a magnitude, while a scalar has only a magnitude, Speed is a scalar quantity.

Q2. The dimensional formula for universal gravitational constant is
सार्वभौमिक गुरुत्वाकर्षण स्थिरता के लिए आयामी सूत्र क्या है?
(a)  [M^(-2)]
(b) [M^(-1) L^3 T^(-2)]
(c) [M^(-1) L^3 T^2]
(d) [ML^2 T^(-2) ]

Show Answer
Ans.(b)
Sol. According to the newton’s law of gravitation, the force of attraction between two objects of mass m_1 and m_2 can be given as F=(Gm_1 m_2)/r^2 , where  G is the gravitational constant and r is the distance between the objects
∴G=(F×r²)/(m_1×m_2 ), now on putting the dimensional formula of F, r, m_1 and m_2 in the given expression, we can get the dimensional formula for G as
([F]×[r]²)/([m_1 ][m_2])=([MLT^2 ]×[L]²)/([M][M])
=[M^(-1 ) L^3   T^(-2)]

Q3. Decibel  is used to measure the intensity of
डेसिबल का उपयोग किस की तीव्रता को मापने के लिए किया जाता है?
(a) Magnetic field/ चुंबकीय क्षेत्र
(b) Sound/ ध्वनि
(c) Light/ प्रकाश
(d) Heat/ऊष्मा

Show Answer
Ans.(b)
Sol. The decibel ( dB) is used to measure sound level, but it is also widely used in electronics, signals and communication. The dB is a logarithmic way of dscribing a ratio. The ratio may be power, sound pressure, voltage or intensity or several other things.

Q4. A micron is equal to
एक माइक्रोन किस के बराबर है-
(a) 0.1 mm
(b) 0.01 mm
(c) 0.001 mm
(d) 0.0001 mm

Show Answer
Ans.(c)
Sol. 1 Microns is equal to 0.001 Millimeters.



Q5   Dimensional formula of latent heat
गुप्त गर्मी का आयामी सूत्र क्या है?
(a) M0L2T-2
(b) MLT-2
(c) ML2T-2
(d) ML2T-2

Show Answer
Ans.(a)
Sol. Latent heat is given by energy per unit mass. The dimensional formula is [M0L2T–2].



Q6. Therm is the unit of
थर्म किस की इकाई है ?
(a) Power/ शक्ति
(b) Heat/ऊष्मा
(c) Light/प्रकाश
(d) Distance/दूरी

Show Answer
Ans.(b)
Sol. The Therm (symbol, thm) is a non-SI unit of heat energy equal to100000 British thermal units (Btu). It is approximately the energy equivalent of burning 100 cubic feet (2.83 cubic metres) – often referred to as 1 CCF – of natural gas.


Q7. Knot is measure of
नॉट क्या मापने में इस्तेमाल किया जाता है?
(a) The speed of ship/जहाज की गति
(b) The curvature of spherical objects/ गोलाकार वस्तुओं का वक्रता
(c) Solar radiation/ सौर विकिरण
(d) Intensity of earthquake shock/ भूकंप की तीव्रता
Show Answer
Ans.(a)
Sol. A knot is one nautical mile per hour (1 knot = 1.15 miles per hour ). The term knot dates from the 17th century, when sailors measured the speed of their ship by using a device called a “common log.” This device was a coil of rope with uniformly spaced knots, attached to a piece of wood shaped like a slice of pie.
Q8. The dimension of which of the following is the same as that of impulse? 
निम्नलिखित में से किस का आयाम आवेग के समान है?
(a) Volume /आयतन
(b) Momentum / संवेग
(c) Torque /टार्क
(d) Change in the rate of momentum / संवेग की दर में बदलाव
Show Answer
Ans.(b)
Sol. Dimensional formula for impulse and momentum are  same  MLT-1.

Q9. Which among the following is the fundamental quantity? 
निम्नलिखित में से क्या एक मौलिक मात्रा है?
(a) Volume /आयतन
(b) Time /समय
(c) Velocity /वेग
(d) Force /बल
Show Answer
Ans.(b)
 Sol. Time in physics is defined by its measurement: time is what a clock reads. In classical, non-relativistic physics it is a scalar quantity and, like length, mass, and charge, is usually described as a fundamental quantity.


Q10. The dimensional formula of coefficient of viscosity is
श्यानता के गुणांक का आयामी सूत्र क्या है?
(a) [MLT-1]
(b) [M-1L2T-2]
(c) [ML-1T-1]
(d) None of these/ इनमें से कोई नहीं
Show Answer
Ans.(c)
 Sol. Coefficient of viscosity is defined as tangential force required to maintain a unit velocity gradient between two parallel layers of liquid of unit area. Mathematically, Coefficient of viscosity (η)= Fr/Av ( where  F= tangential Force, Area, r= distance between the layers, v= velocity.
   viscosity (η)= (MLT-2 x L )/ (L2 x LT-1)
    = (ML2T-2)/L3T-1
     = ML-1T-1.


You may also like to read:

 

Download Upcoming Government Exam Calendar 2021

×

Download success!

Thanks for downloading the guide. For similar guides, free study material, quizzes, videos and job alerts you can download the Adda247 app from play store.

Thank You, Your details have been submitted we will get back to you.

Leave a comment

Your email address will not be published. Required fields are marked *

×
Login
OR

Forgot Password?

×
Sign Up
OR
Forgot Password
Enter the email address associated with your account, and we'll email you an OTP to verify it's you.


Reset Password
Please enter the OTP sent to
/6


×
CHANGE PASSWORD