100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS

1.	If A and B are two physical quantities having different dimensions then which of the following can denote a new physical quantity?A. `A+A^(3)/B`B. `exp (-A/B)`C. `AB^(2)`D. `A/B^(4)`
Answer» Correct Answer - A::C::D For (A): A and `A^(3)/B` may have same dimension. For (B) : As A and B have different dimension so `exp(-A/B)` is meaningless. for (C) : `AB^(2)` is meaningful. for (D) : `AB^(-4)` is meaningful.

Discussion

2.	The position of a particle at time t is given by the relation `x(t)=(v_(0)/alpha)(1-e^(-alphat))` where `v_(0)` is a constant and `alpha gt 0`. Find the dimensions of `v_(0)` and `alpha`
Answer» Dimension of `alphat=M^(0)L^(0)T^(0) rArr "Dimension of" alpha=M^(0)L^(0)T^(-1)` Dimenstion of `(V_(0))/(alpha)=L^(1) rArr` Dimension of `V_(0)=M^(0)L^(0)T^(-1)`

Discussion

3.	In system called the star system we have 1 star kilogram `=10^(20) kg`. 1 starmeter `=10^(8) m`, 1 starsecond `=10^(3)` second then calculate the value of 1 joule in this system.
Answer» Dimension of joule `=ML^(2)T^(-2)` Value of 1 joule in start system `=(10^(-20))(10^(-8))^(2)(10^(-3))^(-2)=10^(-30)` star joule

Discussion

4.	Find dimensional formula: (i) `(dx)/(dt)` (ii) `m(d^(2)x)/(dt^(2))` (iii) `int vdt` (iv) `int adt` where `x rarr` displacement, `t rarr` time, `v rarr` velocity and `a rarr` acceleration
Answer» (i) `[(dx)/(dt)]=[x/t]=[L/T]=[M^(0) L^(1) T^(-1)]` (ii) `[m(d^(2)x)/(dt^(2))]=[m(x)/t^(2)]=[(ML)/T^(2)]=[M^(1) L^(1) T^(-2)]` (iii) `[intvdt]=[vt]=[LT^(-1)xxT]=[M^(0) L^(1) T^(0)]` (iv) `[int adt]=[at]=[LT^(-2)xxT]=[M^(0) L^(1) T^(-1)]`

Discussion

5.	The acceleration due to gravity is `9.8 m s^(-2)`. Give its value in ft `s^(-2)`
Answer» As `1m=3.2` ft `:. 9.8 m//s^(2)=9.8xx3.28 ft//s^(2)=32.14 ft//s^(2) ~~ 32 ft//s^(2)`

Discussion

6.	If `alpha=F/v^(2) sin beta t`, find dimensions of `alpha` and `beta`. Here v=velocity, F= force and t= time.
Answer» Here `sin betat` and `beta t` must be dimensionless So `[beta t]=1rArr[beta]=[(1)/(t)]=[T^(-1)]_(,)[alpha]=[(F)/(v^(2))sin beta t]=[(F)/(v^(2))]=[(MLT^(2))/(L^(2)T^(2))]=[ML^(-1)]`

Discussion

7.	Check the accuracy of the relation `T=sqrt((L)/(g))` for a simple pendulum using dimensional analysis.
Answer» The dimensions of LHS =the dimension of `T=\|M^(0)L^(0)T^(1)\|` The dimensions of RHS `=(("dimensions of length")/("dimensions of acceleration"))^(1//2)` (`therefore 2pi` is a dimensionless constant) `[(L)/(LT^(2))]^(1//2)=[T^(2)]^(1//2)=[T]=[M^(0)L^(0)T^(1)]` Since the dimensions are same on both the sides, the relation is correct.

Discussion

8.	Find dimensional formula :A. `(dx)/(dt)`B. `(d^(2)x)/(dt^(2))`C. `intvdt`D. `intadt`
Answer» (i) `[(dx)/(dt)]=[(x)/(t)]=[(L)/(T)]=[M^(0)L^(1)T^(-1)]` (ii) `[m(d^(2)x)/(dt^(2)]=[m(x)/(T^(2))]=[M^(1)L^(1)T^(2)]` (iii) `[intvdt]=[vt]=[ltLT^()xxT]=[M^(0)L^(1)T^(0)]` (iv) `[intadt]=[at]=[LT^(2)xxT]=[M^(0)L^(1)T^(1)]`

Discussion

9.	It is known that the time of revolution `T` of a satelite around the earth depends on the universal gravitational constant G, the mass of the earth M, and the radius of the circular orbit R. Obtain an expression for `T` using dimensional analysis.
Answer» We have `[T]=[G]^(a)[M]^(a)[R]^(c)` `[M]^(0)[L]^(0)[T]^(1)=[M]^(-a)[L]^(3a)[T]^(-2a)xx[M]^(b)xx[L]^(c)=[M]^(b-a)[L]^(c+3a)[T]^(-2a)` Comparing the exponents For `[T] : 1=-2a rArr a=-1/2` For `[M] : 0=b-a rArr b=a=-1/2` For `[L] : 0=c+3a rArr c=-3a=3/2` Putting the values we get `T prop G^(-1//2) M^(-1//2) R^(3//2) prop sqrt(R^(3)/(GM))` The actual expression is `T=2pisqrt(R^(3)/(GM))`

Discussion

10.	A plank P is placed on a solid cylinder S, which rolls on a horizontal surface. The two are of equal mass. There is no slipping at any of the surfaces in contact. The ratio of the kinetic energy of P to that of S is (a) 1 : 1 (b) 2 : 1 (c) 8 : 3 (d) 11 : 8
Answer» Correct Answer is: (c) 8 : 3 Let v be the velocity of the centre of mass of the cylinder S. Then, the velocity of P is 2v. ∴ KE of P is 1/2 (m)(2v)² = 2mv². KE of S is 1/2 mv²(1 + k²/r²) = 1/2 mv²(1 + 1/2) = 3/4 mv². ∴ The ratio becomes 2mv² : 3/4 mv² = 8 : 3.

10.

A plank P is placed on a solid cylinder S, which rolls on a horizontal surface. The two are of equal mass. There is no slipping at any of the surfaces in contact. The ratio of the kinetic energy of P to that of S is (a) 1 : 1 (b) 2 : 1 (c) 8 : 3 (d) 11 : 8

Answer»

Correct Answer is: (c) 8 : 3

Let v be the velocity of the centre of mass of the cylinder S. Then, the velocity of P is 2v.

∴ KE of P is 1/2 (m)(2v)² = 2mv².

KE of S is 1/2 mv²(1 + k²/r²) = 1/2 mv²(1 + 1/2) = 3/4 mv².

∴ The ratio becomes

2mv² : 3/4 mv² = 8 : 3.

Discussion

11.	It is known that the time of revolution `T` of a satellite around the earth depends on the universal gravitational constant G, the mass of the earth M, and the radius of the circular orbit R. Obtain an expression for `T` using dimensional analysis.
Answer» We have `[T]=[G]^(@) [M]^(@) [R]^(@)` `[M]^(0)[L]^(0)[T]^(1)=[M]^(-a)[L]^(3a)[T]^(-2a)xx[M]^(b-a)[L]^(c+3a)[T]^(-2a)` Comparing the exponents For `[T]: 1=-2arArra=-(1)/(2)` For `[M]: 0-b-arArrb=a=-(1)/(2)` For `[L]: 0=c+3arArrc=-3a=(3)/(2)` Putting the values we get `Tprop G^(-1//2)M^(-1//2)R^(3//2)propsqrt((R^(3))/(GM))` The actual expression is `T=2pisqrt((R^(3))/(GM))`

Discussion

12.	Which of the following electrode is manufactured by circumferential application of heat to a small area of glass tubing and pulling the glass when it gets soft?(a) macro metallic electrodes(b) micro metallic electrodes(c) micro pipette(d) surface electrodes
Answer» Right choice is (c) micro pipette To explain I would say: The most commonly used method for making small tip micropipette consists of the circumferential application of heat to a small area of glass tubing which is placed under some initial tension. When the glass softens, the tension is increased very rapidly and the heat is turned off. Proper timing, controlled adjustment of the amount of heat as well as the initial and final tensions and cooling results in the production of microcapillaries with control dimensions.

Discussion

13.	A wave equation which gives the displacement along the y-direction is given by `y = 10^(-4) sin(60t + 2x)` where `x and y` are in meters and `t` is time in seconds. This represents a waveA. travelling with a velocity of `30 m//s` in the negative x-direction.B. of wavelength `pi m`C. of frequency `30//pi Hz`D. of amplitude `10^-4 m` travelling along the negative x-direction.
Answer» Correct Answer - A::B::C::D `y = 10^(-4) sin (60 t + 2 x)`. Comparing the given equation with the stansard wave equation travelling in negative x-direction, `y = a sin(omega t + kx)` We get amplitude `a = 10^(-4) m` Also `omega = 60` `:. 2 pi f = 60 rArr f = (30)/(pi) Hz` Also, `k = 2` `rArr (2 pi)/(lamda) = 2 rArr lamda = pi m` We know that `v = f lamda = (30)/(pi) xx pi = 30 m//s`.

Discussion

14.	Time is measured using a stop watch of least count 0.1 second In 10 oscilation time taken is 20.0 second Find maximum permissible error in time period .
Answer» `T = ("Total time")/("Total oscillation") = (t)/(10)` `rArr DeltaT = (Deltat)/(10) = (0.1)/(10)` `DeltaT = 0.01` second .

Discussion

15.	In resonance tube exp we find `l_(1) = 25.0 cm` and `l_(2) = 75.0cm` The least count of the scale used to measure l is `0.1cm` If there is no error in frequency What will be max permissible error in speed of sound (take `f_(0) = 325 Hz)` .
Answer» `V = 2f_(0) (l_(2) - l_(1))` `(dV) = 2f_(0) (dl_(2) - dl_(1))` `(DeltaV)_(max) = max of [2f_(0) (+- Deltal_(2) + Deltal_(1))` `Deltal_(1)=` least count of the scale `= 0.1 cm` `Deltal_(2)=` least count of scale `= 0.1 cm` So max permissible error in speed of sound `(DeltaV)_(max) = 2 (325Hz) (0.1 cm + 0.1 cm) = 1.3 m//s` Value of `V = 2f_(0) (l_(2) -l_(1)) = 2 (325 hz) 975.0cm - 25.0 cm) = 325 m//s` so `V = (325 +- 1.3)m//s` .

Discussion

16.	In a resonance tube experiment, resonance occures first at `32.0 cm` and then at `100.0cm`. What is the percentage error in the measurement of end correction.A. `2.5%`B. `5%`C. `7.5%`D. `10%`
Answer» Correct Answer - D In a resonance …………. `e = (l_(3)+3l_(1))/(2) = 2.0cm` `de = (dl_(2)+3dl_(1))/(2)` `% "error" = (dl_(2)+3dl_(1))/(2xxe)xx100` `= (0.1+3xx0.1)/(2xx2.0)xx100=10%`

Discussion

17.	The volume of ascetylene at `NTP` produced by reaction of `50 gm` of `CaC_(2)` with water is : `CaC_(2)+H_(2)O rarr Ca(OH)_(2)+C_(2)H_(2)`A. `10L`B. `17.5L`C. `26.25L`D. `35L`
Answer» Correct Answer - B The volume of …………. `CaC_(2)+2H_(2)O rarr Ca(OH)_(2)+C_(2)H_(2)` , `50 gm` `n_(CaC_(2)) = (50)/(64) = n_(C_(2)H_(2))` Volume `= (50)/(64)xx22.4L = 17.5L`

Discussion

18.	Two disks `A` and `B` are free to rotate about their respective vertical smooth axis passing through their centre as shown. `(R_(A) = 2R_(B), I_(A) = 16 I_(B))`. Disc is rotating about its axis with an angular velocity of `5 rad//sec`. The two disks are moved near to each other till they are in contac. What will be the angular velocity of the smaller disk when slipping between two stops ? A. `8 rad//s`B. `4 rad//s`C. `12 rad//s`D. `5 rad//s`
Answer» Correct Answer - A Two disks ……… If impulse of friction till slipping is `I` then `-IR_(A) = I_(A)omega_(A) = I_(A)xx5` `+IR_(B) = I_(B)omega_(B) - 0` For no slipping `omega_(A)R_(A) = omega_(B)R_(B)` Solving this we get `omega_(B) = 8 rad//s`

Discussion

19.	A uniform rod of length `l` is applied upon by two forces at its either end as shown. Surface is smooth. Which of the following option is correct ? A. Length of rod will remains sameB. Length of rod will decreaseC. Length of rod will increaseD. None of these
Answer» Correct Answer - A A uniform rod …………. `Delta l = 0`

Discussion

20.	A transerverse wave is travelling in x-direction a string having `5N` and liner mass density `50gm//m`. Shape of the string at a particular instant shown in figure. Both `x` and `y` are in meter angle `45^(@)` with x-axis. What is the speed of point `P` of string in `m//s` ? A. `10`B. `5`C. `0.5`D. `1`
Answer» Correct Answer - A A transverse ………… Wave speed, `V_(0) = sqrt((T)/(mu)) = 10m//s` Particle speed, `V. = V_(0) (del y)/(del x) = V_(0) tan 45^(@) = 10 m//s`

Discussion

21.	Patient complain of dry and sandy eyes when receiving large doses of
Answer» Answer: Atropine

Discussion

22.	Velocity of a body on reaching the point, from which it was projected upwards is(1) v = 0 (2) v = 2u (3) v = 0.5u (4) v = u
Answer» Answer is (4) v = u

Discussion

23.	From The First Floor of Qutab Minar which is at a height of 25 m Frum the a man angle observes a. level ground the top of a building at an of elevation of 30 depression of the base of and the angle of the building to be 60° Calculate the height of the building.
Answer» Let the height of the first floor of Qutub Minar be AB = EC = 25 m And DEC (DC) be the height of the tower. BC = AE = Distance between their bases ∠DAE be the angle of elevation of the top of the building. ∠EAC be the angle of depression of the base of the building. In triangle EAC, Tan ∠EAC = EC/AE => √3 = 25/AE => AE = 25/√3 meters In triangle ADE, Tan ∠DAE = DE/AE => 1/√3 = DE/25/√3 => 3DE = 25 => DE = 25/3 => DE = 8.33 approx Height of the building = DE + EC = 8.33 + 25 = 33.33 meters approx. Thus, the height of the building = 33.33 metres.

23.

From The First Floor of Qutab Minar which is at a height of 25 m Frum the a man angle observes a. level ground the top of a building at an of elevation of 30 depression of the base of and the angle of the building to be 60° Calculate the height of the building.

Answer»

Let the height of the first floor of Qutub Minar be AB = EC = 25 m

And DEC (DC) be the height of the tower.

BC = AE = Distance between their bases

∠DAE be the angle of elevation of the top of the building.

∠EAC be the angle of depression of the base of the building.

In triangle EAC,

Tan ∠EAC = EC/AE

=> √3 = 25/AE

=> AE = 25/√3 meters

In triangle ADE,

Tan ∠DAE = DE/AE

=> 1/√3 = DE/25/√3

=> 3DE = 25

=> DE = 25/3

=> DE = 8.33 approx

Height of the building = DE + EC = 8.33 + 25 = 33.33 meters approx.

Thus, the height of the building = 33.33 metres.

Discussion

24.	A man runs towards a mirror at a speed of 15 m/s. what is the speed of this image. (1) 7.5 m/s. (2) 15 m/s. (3) 30 m/s. (4) 45 m/s.
Answer» Answer is (2) 15 m/s. Given : we know that at every instant of time, the image of man will be as far away as the man is in front. Therefore the rate of change of distance of image is same as that of the object (man). Hence the speed of the image is 15 m/s. towards mirror.

24.

A man runs towards a mirror at a speed of 15 m/s. what is the speed of this image. (1) 7.5 m/s. (2) 15 m/s. (3) 30 m/s. (4) 45 m/s.

Answer»

Answer is (2) 15 m/s.

Given : we know that at every instant of time, the image of man will be as far away as the man is in front. Therefore the rate of change of distance of image is same as that of the object (man).

Hence the speed of the image is 15 m/s. towards mirror.

Discussion

25.	A coin falls faster than a scrap of paper when dropped from the same height because for coin :(1) gravitational acceleration is more(2) gravitational acceleration is less.(3) air resistance is less. (4) none of these.
Answer» Answer is (3) air resistance is less. We know that gravitational acceleration is same for all falling bodies. But coin which is heavier body experiences less air resistance as compared to paper. Therefore coins falls faster.

25.

A coin falls faster than a scrap of paper when dropped from the same height because for coin :(1) gravitational acceleration is more(2) gravitational acceleration is less.(3) air resistance is less. (4) none of these.

Answer»

Answer is (3) air resistance is less.

We know that gravitational acceleration is same for all falling bodies. But coin which is heavier body experiences less air resistance as compared to paper. Therefore coins falls faster.

Discussion

26.	A student measured the diameter of a wire using a screw gauge with least count `0.001cm` and listed the measurement. The correct measurement isA. 5.3cmB. 5.32cmC. 5.320 cmD. 5.3200 cm
Answer» The correct value of diameter is upto 3 digits after the decimal as the elast count is 0.001 cm

Discussion

27.	Give the general characteristics of organic compounds
Answer» The general characteristics of Organic Compounds are: Organic compounds include complex structures and high molecular weights. These are soluble in organic solvents and mostly insoluble in water. Mostly depend on only three elements: Carbon, Hydrogen and nitrogen. These compounds are combustible in nature. Most properties of the compounds are decided by the functional group attached to them.

27.

Give the general characteristics of organic compounds

Answer»

The general characteristics of Organic Compounds are:

Organic compounds include complex structures and high molecular weights.
These are soluble in organic solvents and mostly insoluble in water.
Mostly depend on only three elements: Carbon, Hydrogen and nitrogen.
These compounds are combustible in nature.
Most properties of the compounds are decided by the functional group attached to them.

Discussion

28.	What amount of heat would be required to produce 4.4 kg of steam at a pressure of 6 bar and temperature of 250°C from water at 30°C ? Take specific heat for superheated steam as 2.2 kJ/kg K.
Answer» Mass of steam to be produced, m = 4.4 kg Pressure of steam, p = 6 bar Temperature of steam, t_sup = 250°C Temperature of water = 30°C Specific heat of steam, c_ps = 2.2 kJ/kg At 6 bar, 250°C : From steam tables, t_s = 158.8°C, h_f = 670.4 kJ/kg, h_fg = 2085 kJ/kg Enthalpy of 1 kg superheated steam reckoned from 0°C, h_sup = h_f + h_fg + cps (T_sup – T_s ) = 670.4 + 2085 + 2.2(250 – 158.8) = 2956 kJ Amount of heat already with 1 kg of water = 1 × 4.18 × (30 – 0) = 125.4 kJ Net amount of heat required to be supplied per kg = 2956 – 125.4 = 2830.6 kJ Total amount of heat required = 4.4 × 2830.6 = 12454.6 kJ.

28.

What amount of heat would be required to produce 4.4 kg of steam at a pressure of 6 bar and temperature of 250°C from water at 30°C ? Take specific heat for superheated steam as 2.2 kJ/kg K.

Answer»

Mass of steam to be produced, m = 4.4 kg

Pressure of steam, p = 6 bar

Temperature of steam, t_sup = 250°C

Temperature of water = 30°C

Specific heat of steam, c_ps = 2.2 kJ/kg

At 6 bar, 250°C : From steam tables,

t_s = 158.8°C, h_f = 670.4 kJ/kg, h_fg = 2085 kJ/kg

Enthalpy of 1 kg superheated steam reckoned from 0°C,

h_sup = h_f + h_fg + cps (T_sup – T_s )

= 670.4 + 2085 + 2.2(250 – 158.8)

= 2956 kJ

Amount of heat already with 1 kg of water

= 1 × 4.18 × (30 – 0) = 125.4 kJ

Net amount of heat required to be supplied per kg

= 2956 – 125.4 = 2830.6 kJ

Total amount of heat required

= 4.4 × 2830.6 = 12454.6 kJ.

Discussion

29.	Determine the amount of heat, which should be supplied to 2 kg of water at 25°C to convert it into steam at 5 bar and 0.9 dry.
Answer» Mass of water to be converted to steam, m_w = 2 kg Temperature of water, t_w = 25°C Pressure and dryness fraction of steam = 5 bar, 0.9 dry At 5 bar : From steam tables h_f = 640.1 kJ/kg ; h_fg = 2107.4 kJ/kg Enthalpy of 1 kg of steam (above 0°C) h = h_f + xh_fg = 640.1 + 0.9 × 2107.4 = 2536.76 kJ/kg Sensible heat associated with 1 kg of water m_w × c_pw × (t_w – 0) = 1 × 4.18 × (25 – 0) = 104.5 kJ Net quantity of heat to be supplied per kg of water = 2536.76 – 104.5 = 2432.26 kJ Total amount of heat to be supplied = 2 × 2432.26 = 4864.52 kJ.

29.

Determine the amount of heat, which should be supplied to 2 kg of water at 25°C to convert it into steam at 5 bar and 0.9 dry.

Answer»

Mass of water to be converted to steam, m_w = 2 kg

Temperature of water, t_w = 25°C

Pressure and dryness fraction of steam = 5 bar, 0.9 dry

At 5 bar : From steam tables

h_f = 640.1 kJ/kg ; h_fg = 2107.4 kJ/kg

Enthalpy of 1 kg of steam (above 0°C)

h = h_f + xh_fg

= 640.1 + 0.9 × 2107.4 = 2536.76 kJ/kg

Sensible heat associated with 1 kg of water

m_w × c_pw × (t_w – 0)

= 1 × 4.18 × (25 – 0) = 104.5 kJ

Net quantity of heat to be supplied per kg of water

= 2536.76 – 104.5 = 2432.26 kJ

Total amount of heat to be supplied

= 2 × 2432.26 = 4864.52 kJ.

Discussion

30.	If a certain amount of steam is produced at a pressure of 8 bar and dryness fraction 0.8. Calculate : (i) External work done during evaporation. (ii) Internal latent heat of steam.
Answer» Pressure of steam, p = 8 bar Dryness fraction, x = 0.8 At 8 bar. From steam tables, v_g = 0.240 m³/kg, h_fg = 2046.5 kJ/kg (i) External work done during evaporation = pxv_g= 8 × 10⁵ × 0.8 × 0.24 N-m = \(\cfrac{8\times10^5\times0.8\times0.24}{10^3}\) = 153.6 kJ. (ii) Internal latent heat = xh_fg – external work done = 0.8 × 2046.5 – 153.6 = 1483.6 kJ.

30.

If a certain amount of steam is produced at a pressure of 8 bar and dryness fraction 0.8. Calculate : (i) External work done during evaporation. (ii) Internal latent heat of steam.

Answer»

Pressure of steam, p = 8 bar

Dryness fraction, x = 0.8

At 8 bar. From steam tables,

v_g = 0.240 m³/kg, h_fg = 2046.5 kJ/kg

(i) External work done during evaporation

= pxv_g= 8 × 10⁵ × 0.8 × 0.24 N-m

= \(\cfrac{8\times10^5\times0.8\times0.24}{10^3}\) = 153.6 kJ.

(ii) Internal latent heat

= xh_fg – external work done

= 0.8 × 2046.5 – 153.6

= 1483.6 kJ.

Discussion

31.	What are the advantages of piezoelectric microphone? Where is it used?
Answer» Advantages: 1. It is available in desired shape. 2. It has rugged construction. 3. It is small in size. 4. It has good frequency response. 5. It has negligible phase shift. Applications: The piezoelectric transducer is used in spark ignition engines. It can be used in electronic watches. It is used in accelerometer. It is used in record player.

31.

What are the advantages of piezoelectric microphone? Where is it used?

Answer»

Advantages:

1. It is available in desired shape.

2. It has rugged construction.

3. It is small in size.

4. It has good frequency response.

5. It has negligible phase shift.

Applications:

The piezoelectric transducer is used in spark ignition engines.
It can be used in electronic watches.
It is used in accelerometer.
It is used in record player.

Discussion

32.	When in a TV receiver both sound and picture are weak and distorted, the problem is most likely in (a) AFC (b) FMD etector (c) Tuner (d) Video Amp
Answer» Correct option: (c) tuner

Discussion

33.	Srinu, while playing with a bar magnet, brought it close to the TV screen. He was surprised to see the screen distorted. What might be the reason ?
Answer» When a bar magnet is placed near to the TV screen then the motion of electrons are affected by the field produced by the bar magnet. So, the picture on TV screen is distorted.

Discussion

34.	The most suitable refrigeration system utilizing solar energy is : (a) Ammonia-Water vapour absorption refrigeration system (b) Lithium Bromide-Water vapour absorption refrigeration system (c) Desiccant refrigeration system (d) Thermoelectric refrigeration system
Answer» (a) Ammonia-Water vapour absorption refrigeration system Ammonia-water absorption is more suitable for refrigeration than lithium bromide (LiBr) water absorption using solar energy. In LiBr, water is refrigerant and LiBr is absorbent so water freezes as temperature decreases to 0°C.

34.

The most suitable refrigeration system utilizing solar energy is : (a) Ammonia-Water vapour absorption refrigeration system (b) Lithium Bromide-Water vapour absorption refrigeration system (c) Desiccant refrigeration system (d) Thermoelectric refrigeration system

Answer»

(a) Ammonia-Water vapour absorption refrigeration system

Ammonia-water absorption is more suitable for refrigeration than lithium bromide (LiBr) water absorption using solar energy. In LiBr, water is refrigerant and LiBr is absorbent so water freezes as temperature decreases to 0°C.

Discussion

35.	In a solar collector, the function of the transparent cover is to : (a) Transmit solar radiation only (b) Protect the collector from dust (c) Decrease the heat loss from collector beneath to atmosphere (d) Absorb all types of radiation and protect the collector from dust
Answer» (c) Decrease the heat loss from collector beneath to atmosphere The purpose of transparent cover is to transmit the shorter wavelength solar radiation but block longer wavelength reradiation from the absorber plate and to reduce the heat loss by convection from top of the absorber plate.

35.

In a solar collector, the function of the transparent cover is to : (a) Transmit solar radiation only (b) Protect the collector from dust (c) Decrease the heat loss from collector beneath to atmosphere (d) Absorb all types of radiation and protect the collector from dust

Answer»

(c) Decrease the heat loss from collector beneath to atmosphere

The purpose of transparent cover is to transmit the shorter wavelength solar radiation but block longer wavelength reradiation from the absorber plate and to reduce the heat loss by convection from top of the absorber plate.

Discussion

36.	The discharge through an orifice fitted in a tank can be increased by : (a) Fitting a short length of pipe to the outside (b) Sharpening the edge of orifice (c) Fitting a long length of pipe to the outside (d) Fitting a long length of pipe to the inside
Answer» (a) Fitting a short length of pipe to the outside By fitting long pipe discharge will be more but less in comparison of short length pipe due to more friction loss in long pipe. When pipe is fitted outside in that case coefficient of discharge is around 0.82 and when it fitted inside then same is of 0.75. So, pipe of short length fitted outside give more discharge

36.

The discharge through an orifice fitted in a tank can be increased by : (a) Fitting a short length of pipe to the outside (b) Sharpening the edge of orifice (c) Fitting a long length of pipe to the outside (d) Fitting a long length of pipe to the inside

Answer»

(a) Fitting a short length of pipe to the outside

By fitting long pipe discharge will be more but less in comparison of short length pipe due to more friction loss in long pipe.

When pipe is fitted outside in that case coefficient of discharge is around 0.82 and when it fitted inside then same is of 0.75. So, pipe of short length fitted outside give more discharge

Discussion

37.	The latent heat load in an auditorium is 25% of sensible heat load. The value of sensible heat factor is (a) 0.3 (b) 0.5 (c) 0.8 (d) 1.0
Answer» (c) 0.8 Latent heat load, = 25% of sensible heat. LHL = 25% SHL = 0.25 SHL Sensible heat factor SHF = \(\frac{SHL }{SHL +LHL}\) = \(\frac{SHL }{SHL +0.25\,SHL}\) = \(\frac1{1.25}\) = 0.8

37.

The latent heat load in an auditorium is 25% of sensible heat load. The value of sensible heat factor is (a) 0.3 (b) 0.5 (c) 0.8 (d) 1.0

Answer»

(c) 0.8

Latent heat load, = 25% of sensible heat.

LHL = 25% SHL = 0.25 SHL

Sensible heat factor

SHF = \(\frac{SHL }{SHL +LHL}\) = \(\frac{SHL }{SHL +0.25\,SHL}\)

= \(\frac1{1.25}\) = 0.8

Discussion

38.	In a sensible heating process, the change takes place in D.B.T. of air is (a) Decrease (b) Increase (c) No change (d) Decrease and increase both
Answer» Correct option: (b) Increase

Discussion

39.	The air cooled condensers employing fans or blowers to provide air circulation are known as (a) Forced convection air cooled condensers (b) Natural convection air cooled condensers (c) Water cooled condensers (d) Evaporative condensers
Answer» Correct option: (a) Forced convection air cooled condensers

Discussion

40.	The natural colour of this fibre is : a. White, green, brown and black b. Blue, gray, brown and black c. White, gray, brown and black d. Cream, beige, brown and black
Answer» c. White, gray, brown and black The natural colour of this fibre is White, gray, brown and black.

40.

The natural colour of this fibre is : a. White, green, brown and black b. Blue, gray, brown and black c. White, gray, brown and black d. Cream, beige, brown and black

Answer»

c. White, gray, brown and black

The natural colour of this fibre is White, gray, brown and black.

Discussion

41.	What is the consumer use of this fibre? a. In apparel, it is used in outer wear for its warmth and durability. b. In apparel, it is used in outer wear for its light weight and durability. c. In apparel, it is used in outer wear for its warmth and lustre. d. In apparel, it is used in outer wear for its light weight and luster.
Answer» a. In apparel, it is used in outer wear for its warmth and durability. The consumer use of this fibre In apparel, it is used in outer wear for its warmth and durability.

41.

What is the consumer use of this fibre? a. In apparel, it is used in outer wear for its warmth and durability. b. In apparel, it is used in outer wear for its light weight and durability. c. In apparel, it is used in outer wear for its warmth and lustre. d. In apparel, it is used in outer wear for its light weight and luster.

Answer»

a. In apparel, it is used in outer wear for its warmth and durability.

The consumer use of this fibre In apparel, it is used in outer wear for its warmth and durability.

Discussion

42.	The material used for isolating the warm surroundings from the cold refrigerated spaces is known as (a) Electrical conducting material (b) Thermal conducting material (c) Electrical insulating material (d) Thermal insulating material
Answer» Correct option: (d) Thermal insulating material

Discussion

43.	The reaction `2A+Bto` product follow the mechanism :- `2AhArrA_(2)("fast")` `A_(2)+BtoP(slow)` `The order of the reaction isA. 1.5B. 3C. 1D. 2
Answer» Correct Answer - B `r=K(A_(2))(B)Kto(A_(2))/((A)^(2))(A_(2))=K(A)^(2)` `r=KK(A)^(2)(B)^(1)ton=3`

Discussion

44.	Write a note on (a) Maturity date (b) Front and backend interest.
Answer» (a) The maturity of a promissory note or bill of exchange is the date at which it falls due for payment. (b) Front end interest is interest calculated at the beginning of the loan installment, in advance, whereas the back end interest is interest calculated at the end of the installment when interest amounts fall due.

44.

Write a note on (a) Maturity date (b) Front and backend interest.

Answer»

(a) The maturity of a promissory note or bill of exchange is the date at which it falls due for payment.

(b) Front end interest is interest calculated at the beginning of the loan installment, in advance, whereas the back end interest is interest calculated at the end of the installment when interest amounts fall due.

Discussion

45.	What is EMI? Explain its formula used for calculations.
Answer» An Equated Monthly Instalment (EMI) is defined as "Payment of a fixed payment amount made by a borrower to a lender at a specified date each calendar month. Equated monthly instalments are used to pay off both interest and principal each month, so that over a specified number of years, the loan is fully paid off along with interest." EMI = [(Pr/1200)(1+r/1200)^N] / [(1+r/1200) – 1]

45.

What is EMI? Explain its formula used for calculations.

Answer»

An Equated Monthly Instalment (EMI) is defined as "Payment of a fixed payment amount made by a borrower to a lender at a specified date each calendar month. Equated monthly instalments are used to pay off both interest and principal each month, so that over a specified number of years, the loan is fully paid off along with interest."

EMI = [(P*r/1200)*(1+r/1200)^N] / [(1+r/1200) – 1]

Discussion

46.	How many days are added as days of grace while calculating the due date of a bill ? Find the due date for the following bills:i) Bill drawn on 1st January,2015 payable one month after the date. ii) Bill drawn on 29th December, 2015 payable two months after the date.
Answer» Three days of grace are added. 1. Bill drawn on 1^st January, 2015 payable one month after the date. (4 Feb.2015) 2. Bill drawn on 29^th December, 2015 payable two months after the date. (1 Feb. 2015)

46.

How many days are added as days of grace while calculating the due date of a bill ? Find the due date for the following bills:i) Bill drawn on 1st January,2015 payable one month after the date. ii) Bill drawn on 29th December, 2015 payable two months after the date.

Answer»

Three days of grace are added.

1. Bill drawn on 1^st January, 2015 payable one month after the date. (4 Feb.2015)

2. Bill drawn on 29^th December, 2015 payable two months after the date. (1 Feb. 2015)

Discussion

47.	What’s his name? A) It John. B) It’s John. C) John it’s the name. D) Its John.
Answer» Correct option is B) It’s John

Discussion

48.	……. days of grace are allowed in case of time bills for calculating the date of maturity.
Answer» Three days of grace are allowed in case of time bills for calculating the date of maturity.

Discussion

49.	The car had been left _____ the side of the road. A) on B) with C) at D) in
Answer» Correct option is C) at

Discussion

50.	Is John tall? A) Yes, he’s. B) No, he’sn’t. C) No, his not. D) Yes, he is.
Answer» Correct option is D) Yes, he is.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

If A and B are two physical quantities having different dimensions then which of the following can denote a new physical quantity?A. `A+A^(3)/B`B. `exp (-A/B)`C. `AB^(2)`D. `A/B^(4)`

The position of a particle at time t is given by the relation `x(t)=(v_(0)/alpha)(1-e^(-alphat))` where `v_(0)` is a constant and `alpha gt 0`. Find the dimensions of `v_(0)` and `alpha`

In system called the star system we have 1 star kilogram `=10^(20) kg`. 1 starmeter `=10^(8) m`, 1 starsecond `=10^(3)` second then calculate the value of 1 joule in this system.

Find dimensional formula: (i) `(dx)/(dt)` (ii) `m(d^(2)x)/(dt^(2))` (iii) `int vdt` (iv) `int adt` where `x rarr` displacement, `t rarr` time, `v rarr` velocity and `a rarr` acceleration

The acceleration due to gravity is `9.8 m s^(-2)`. Give its value in ft `s^(-2)`

If `alpha=F/v^(2) sin beta t`, find dimensions of `alpha` and `beta`. Here v=velocity, F= force and t= time.

Check the accuracy of the relation `T=sqrt((L)/(g))` for a simple pendulum using dimensional analysis.

Find dimensional formula :A. `(dx)/(dt)`B. `(d^(2)x)/(dt^(2))`C. `intvdt`D. `intadt`

It is known that the time of revolution `T` of a satelite around the earth depends on the universal gravitational constant G, the mass of the earth M, and the radius of the circular orbit R. Obtain an expression for `T` using dimensional analysis.

A plank P is placed on a solid cylinder S, which rolls on a horizontal surface. The two are of equal mass. There is no slipping at any of the surfaces in contact. The ratio of the kinetic energy of P to that of S is (a) 1 : 1 (b) 2 : 1 (c) 8 : 3 (d) 11 : 8

It is known that the time of revolution `T` of a satellite around the earth depends on the universal gravitational constant G, the mass of the earth M, and the radius of the circular orbit R. Obtain an expression for `T` using dimensional analysis.

Which of the following electrode is manufactured by circumferential application of heat to a small area of glass tubing and pulling the glass when it gets soft?(a) macro metallic electrodes(b) micro metallic electrodes(c) micro pipette(d) surface electrodes

Time is measured using a stop watch of least count 0.1 second In 10 oscilation time taken is 20.0 second Find maximum permissible error in time period .

In resonance tube exp we find `l_(1) = 25.0 cm` and `l_(2) = 75.0cm` The least count of the scale used to measure l is `0.1cm` If there is no error in frequency What will be max permissible error in speed of sound (take `f_(0) = 325 Hz)` .

In a resonance tube experiment, resonance occures first at `32.0 cm` and then at `100.0cm`. What is the percentage error in the measurement of end correction.A. `2.5%`B. `5%`C. `7.5%`D. `10%`

The volume of ascetylene at `NTP` produced by reaction of `50 gm` of `CaC_(2)` with water is : `CaC_(2)+H_(2)O rarr Ca(OH)_(2)+C_(2)H_(2)`A. `10L`B. `17.5L`C. `26.25L`D. `35L`

A uniform rod of length `l` is applied upon by two forces at its either end as shown. Surface is smooth. Which of the following option is correct ? A. Length of rod will remains sameB. Length of rod will decreaseC. Length of rod will increaseD. None of these

Patient complain of dry and sandy eyes when receiving large doses of

Velocity of a body on reaching the point, from which it was projected upwards is(1) v = 0 (2) v = 2u (3) v = 0.5u (4) v = u

From The First Floor of Qutab Minar which is at a height of 25 m Frum the a man angle observes a. level ground the top of a building at an of elevation of 30 depression of the base of and the angle of the building to be 60° Calculate the height of the building.

A man runs towards a mirror at a speed of 15 m/s. what is the speed of this image. (1) 7.5 m/s. (2) 15 m/s. (3) 30 m/s. (4) 45 m/s.

A coin falls faster than a scrap of paper when dropped from the same height because for coin :(1) gravitational acceleration is more(2) gravitational acceleration is less.(3) air resistance is less. (4) none of these.

A student measured the diameter of a wire using a screw gauge with least count `0.001cm` and listed the measurement. The correct measurement isA. 5.3cmB. 5.32cmC. 5.320 cmD. 5.3200 cm

Give the general characteristics of organic compounds

What amount of heat would be required to produce 4.4 kg of steam at a pressure of 6 bar and temperature of 250°C from water at 30°C ? Take specific heat for superheated steam as 2.2 kJ/kg K.

Determine the amount of heat, which should be supplied to 2 kg of water at 25°C to convert it into steam at 5 bar and 0.9 dry.

If a certain amount of steam is produced at a pressure of 8 bar and dryness fraction 0.8. Calculate : (i) External work done during evaporation. (ii) Internal latent heat of steam.

What are the advantages of piezoelectric microphone? Where is it used?

When in a TV receiver both sound and picture are weak and distorted, the problem is most likely in (a) AFC (b) FMD etector (c) Tuner (d) Video Amp

Srinu, while playing with a bar magnet, brought it close to the TV screen. He was surprised to see the screen distorted. What might be the reason ?

The most suitable refrigeration system utilizing solar energy is : (a) Ammonia-Water vapour absorption refrigeration system (b) Lithium Bromide-Water vapour absorption refrigeration system (c) Desiccant refrigeration system (d) Thermoelectric refrigeration system

In a solar collector, the function of the transparent cover is to : (a) Transmit solar radiation only (b) Protect the collector from dust (c) Decrease the heat loss from collector beneath to atmosphere (d) Absorb all types of radiation and protect the collector from dust

The discharge through an orifice fitted in a tank can be increased by : (a) Fitting a short length of pipe to the outside (b) Sharpening the edge of orifice (c) Fitting a long length of pipe to the outside (d) Fitting a long length of pipe to the inside

The latent heat load in an auditorium is 25% of sensible heat load. The value of sensible heat factor is (a) 0.3 (b) 0.5 (c) 0.8 (d) 1.0

In a sensible heating process, the change takes place in D.B.T. of air is (a) Decrease (b) Increase (c) No change (d) Decrease and increase both

The air cooled condensers employing fans or blowers to provide air circulation are known as (a) Forced convection air cooled condensers (b) Natural convection air cooled condensers (c) Water cooled condensers (d) Evaporative condensers

The natural colour of this fibre is : a. White, green, brown and black b. Blue, gray, brown and black c. White, gray, brown and black d. Cream, beige, brown and black

The material used for isolating the warm surroundings from the cold refrigerated spaces is known as (a) Electrical conducting material (b) Thermal conducting material (c) Electrical insulating material (d) Thermal insulating material

The reaction `2A+Bto` product follow the mechanism :- `2AhArrA_(2)("fast")` `A_(2)+BtoP(slow)` `The order of the reaction isA. 1.5B. 3C. 1D. 2

Write a note on (a) Maturity date (b) Front and backend interest.

What is EMI? Explain its formula used for calculations.

How many days are added as days of grace while calculating the due date of a bill ? Find the due date for the following bills:i) Bill drawn on 1st January,2015 payable one month after the date. ii) Bill drawn on 29th December, 2015 payable two months after the date.

What’s his name? A) It John. B) It’s John. C) John it’s the name. D) Its John.

……. days of grace are allowed in case of time bills for calculating the date of maturity.

The car had been left _____ the side of the road. A) on B) with C) at D) in

Is John tall? A) Yes, he’s. B) No, he’sn’t. C) No, his not. D) Yes, he is.