# SSC Scientific Assistant (IMD) Exam : Held on 22-Nov-2017 Shift-2 (Physics)

## SSC Scientific Assistant (IMD) Exam : Held on 22 Nov 2017 Shift-2

## (Physics)

**QID : 701 **- In the ideal gas equation, PV = µRT, µ is the ________________ of the gas.

**Options:**

1) density

2) viscosity

3) thermal coefficient of volume expansion

4) number of moles**Correct Answer**: number of moles**QID : 702 **- "To every action, there is always an equal and opposite reaction." This statement is ________________.

**Options:**

1) Newton's 1st Law

2) Newton's 2nd Law

3) Law of conservation of energy

4) Newton's 3rd Law**Correct Answer**: Newton's 3rd Law**QID : 703 **- [M^{-1}L^{3}T^{-2}] are the dimensions of? **Options**:

1) Gravitational constant

2) Gravitational potential energy

3) Gravitational potential

4) Gravitational intensity**Correct Answer**: Gravitational constant

**QID : 704 -**

**Options**:

1) A-2, B-3, C-1

2) A-3, B-2, C-1

3) A-2, B-1, C-3

4) A-3, B-1, C-2**Correct Answer**: A-3, B-2, C-1

**(EBOOK) SSC Scientific Assistant (IMD) Exam Papers PDF Download**

## Study Kit for SSC Scientific Assistant (IMD) Examination

**QID : 705 **- 1 atomic mass unit (u) is equivalent to ____________ the mass of carbon isotope C-12.

**Options**:

1) 12 times

2) 1/12th

3) 1/6th

4) 6 times**Correct Answer**: 1/12th

**QID : 706 **- _{1}n^{0} + _{235}U^{92} → _{140}Ba^{56} + _{y}Kr^{36} + _{31}n^{0}. Find y from the given fission equation of an uranium nucleus?

**Options**:

1) 91

2) 95

3) 93

4) 92**Correct Answer**: 93**QID : 707 **- What does 32^{o} Fahrenheit equals to?

**Options**:

1) 373.15 K

2) 100o C

3) 89.6o C

4) 273.15 K**Correct Answer**: 273.15 K**QID : 708 **- 4_{1}H^{1} → _{4}He^{2} + _________ + energy. Find the missing element/s.

**Options**:

1) 2 neutrons

2) 2 electrons

3) 2 protons

4) 2 positrons**Correct Answer**: 2 positrons

**QID : 709 **- A ball is thrown vertically upwards with a velocity of 20 m/s. How high will the ball rise (in meters)? (use g = 10 m/s²)

**Options**:

1) 10

2) 20

3) 5

4) 40**Correct Answer**: 20**QID : 710 **- A boy standing on a 20 m tall building throws a stone horizontally with a speed of 15 m/s. With what speed will the stone hit the ground (in m/s)? (use g = 10 m/s²)

**Options**:

1) 20

2) 25

3) 15

4) 10**Correct Answer**: 25**QID : 711 **- A cyclic heat engine does 24kJ of work per cycle. If the efficiency of the engine is 0.8, then what will be the heat (in kJ) rejected per cycle?

**Options**:

1) 30

2) 6

3) 19.2

4) 39.2**Correct Answer**: 6**QID : 712 **- A mono atomic molecule free to move in space has how many translational degrees of freedom?

**Options**:

1) three

2) two

3) one

4) five**Correct Answer**: three

**QID : 713 -**

**Options**:

1) 50

2) 6

3) 40

4) 8**Correct Answer**: 8**QID : 714 **- A point of maximum positive displacement in a transverse wave is called?

**Options**:

1) trough

2) vertex

3) apex

4) crest**Correct Answer**: crest**QID : 715 **- A ray emanating from the object parallel to the principal axis of a convex lens after refraction _______________.

**Options:**

1) passes through the second principal focus

2) passes through the center of curvature

3) passes through the pole

4) remains parallel to the principal axis**Correct Answer**: passes through the second principal focus**QID : 716 **- A resistor which has a silver coloured ring signifies that the resistor has __________ percent tolerance.

**Options**:

1) 10

2) 5

3) 1

4) 20**Correct Answer**: 10**QID : 717 **- An adiabatic wall between two thermodynamic systems _____________.

**Options:**

1) allows both heat and matter to pass across it at constant temperature

2) does not allow heat to pass across it but allows matter to pass

3) does not allow matter to pass but allows heat to pass across it

4) does not allow heat or matter to pass across it**Correct Answer**: does not allow heat or matter to pass across it**QID : 718 -** An alpha particle is same as?

**Options**:

1) a helium nucleus

2) a hydrogen nucleus

3) a proton

4) a positron**Correct Answer**: a helium nucleus

**QID : 719 - **At what temperature (in oC) is the r.m.s. velocity of hydrogen molecules twice the r.m.s. velocity of oxygen molecules at 327o C?

**Options**:

1) 150

2) -123

3) -150

4) 123**Correct Answer**: -123**QID : 720 **- B/µo - M is equal to? (B is magnetic field, M is magnetisation of the material and µo is permeability of free space)

**Options**:

1) magnetic susceptibility

2) magnetic moment

3) magnetic intensity

4) magnetic flux**Correct Answer**: magnetic intensity

**QID : 721 **- By what percent should the pressure of a gas be increased so as to decrease its volume by 20%, at constant temperature?

**Options**:

1) 20%

2) 16%

3) 25%

4) 40%**Correct Answer**: 25%**QID : 722 **- Electric potential at a point with position vector r due to a point charge Q placed at the origin is given by the formula _____________.

**Options**:

1) V = Q/(2π?or2)

2) V = Q/(4π?or2)

3) V = Q/(4π?or)

4) V = Q/(2π?or)**Correct Answer**: V = Q/(4π?or)**QID : 723 **- Fermi is a unit of?

**Options**:

1) Length

2) Mass

3) Area

4) Time**Correct Answer**: Length**QID : 724 **- Find the uniform angular acceleration of a wheel if its angular speed increases from 420 rpm to 660 rpm in 8 seconds?

**Options:**

1) 2? rad/s²

2) 1 rad/s²

3) ? rad/s²

4) 2 rad/s²**Correct Answer**: ? rad/s²**QID : 725 **- For a transistor in common emitter configuration ____________________ is the ratio of change in base-emitter voltage (ΔVBE) to the resulting change in base current (ΔIB) at constant collector-emitter voltage (VCE).

**Options:**

1) Output resistance

2) Current amplification factor

3) Voltage gain

4) Input resistance**Correct Answer**: Input resistance**QID : 726 **- For small deformations, the stress and strain are proportional to each other. What is this known as?

**Options**:

1) Hooke’s law

2) Gauss's Law

3) Henry's Law

4) Joule's Law**Correct Answer**: Hooke’s law

**QID : 727 **- How much heat (in joules) would be required to raise the temperature of 500 g of an aluminium sphere from 20 oC to 720 oC? [Specific Heat Capacity of Aluminium is 900 J/(kgK)]

**Options**:

1) 3.15 x 105

2) 3.15 x 107

3) 1.26 x 105

4) 1.26 x 107**Correct Answer**: 3.15 x 105

**QID : 728 **- If 1,2 and 3 represent different mediums and 'n' is refractive index, then which of the following equations is true?

**Options**:

1) n23 = n31 × n12

2) n32 = n31 × n12

3) n32 = n13 × n12

4) n23 = n13 × n12**Correct Answer**: n32 = n31 × n12**QID : 729 **- If 'A' is the angle of a prism, 'I' is angle of incidence, 'e' is angle of emergence, then the angle of deviation 'δ' of light incident on the prism is equal to?

**Options**:

1) i + e + A

2) i - e + A

3) i - e - A

4) i + e - A**Correct Answer**: i + e - A**QID : 730 -** If a metal wire of length 'l' and cross section area 'A' has resistance 'R', then the resistivity of the material of the wire is equal to?

**Options:**

1) RA/l

2) Rl/A

3) lA/R

4) A/(lR)**Correct Answer**: RA/l

**QID : 731 **- If a projectile is thrown with velocity v and makes an angle θ with the x-axis then the time taken for achieving maximum height is given by which formula?

**Options**:

1) t= vsinθ/g

2) t= v²sinθ/g

3) t= v²sin²θ/g

4) t= vsin²θ/g**Correct Answer**: t= vsinθ/g**QID : 732 **- If an object is placed 10 cm in front of a convex lens of focal length 6 cm, then find the position of the image (in cm)?

**Options**:

1) 12

2) -15

3) 15

4) -12**Correct Answer**: 15

**QID : 733 **- If chlorine has two isotopes one of 35u and the other 37u and the average mass of chlorine atom is 35.5u, then the ratio of abundance of the two isotopes of masses 35u and 37u is _______.

**Options**:

1) 1/3

2) 1/4

3) 3/1

4) 4/1**Correct Answer**: 3/1**QID : 734** - If 'E' is magnitude of uniform electric field in a conductor, 'τ' is the relaxation time, ('e' is charge and'm' is mass of an electron) then, the term -eEτ/m is equal to the ______________ the electrons.

**Options**:

1) force experienced by

2) acceleration experienced by

3) drift velocity of

4) charge density due to**Correct Answer**: drift velocity of**QID : 735** - If the empirical formula for the observed wavelengths for hydrogen is 1/λ = R(1/12 - 1/n2), where n is integral values higher than 1, then it represents the _____________ spectral series.

**Options**:

1) Balmer

2) Paschen

3) Lyman

4) Brackett**Correct Answer**: Lyman**QID : 736 **- If the energy of the electron in the 2nd orbit of hydrogen is -3.4 eV, then how much is the energy (in eV) in the 3rd orbit?

**Options**:

1) -1.511

2) -2.22

3) -5.1

4) -13.6**Correct Answer**: -1.511**QID : 737 **- If the gas particles are of diameter 'd', average speed 'v', number of particles per unit volume 'n', then the volume a particle sweeps in time 't' is?

**Options**:

1) ?d2vt

2) ?v2td

3) ?t2vd

4) ?2tvd**Correct Answer**: ?d2vt

**QID : 738** - If the ideal gas equation is written as PV = kBNT, where N is number of molecules, then kB represents?

**Options**:

1) Gas Constant

2) Bohr radius

3) Boltzmann constant

4) B-Factor**Correct Answer**: Boltzmann constant**QID : 739 -** If x is displacement, time taken is t, initial velocity is u, final velocity is v and acceleration is a, then which of the following equations is true?

**Options**:

1) u² = v² + 2ax

2) x = (v² - u²)/2a

3) v² = u² - 2ax

4) x = (v² + u²)/2a**Correct Answer**: x = (v² - u²)/2a**QID : 740** - If 'x' is the displacement of a particle performing simple harmonic motion, then "kx2/2" is equal to its ______________ energy.

**Options**:

1) kinetic

2) potential

3) total mechanical

4) vibrational**Correct Answer**: potential

**QID : 741** - If 'φ' is Electric flux through a closed surface 'S', 'q' is total charge enclosed by 'S' and '?'o is permittivity of free space, then these three are related by Gauss' Law formula __________.

**Options**:

1) φ = q?o

2) φ = q/?o

3) φ = ?o/q

4) φ = √(q?o)**Correct Answer**: φ = q/?o**QID : 742** - In ______________the conduction band overlaps on the valence band.

**Options**:

1) elemental semiconductors

2) compound semiconductors

3) metallic conductors

4) insulators**Correct Answer**: metallic conductors**QID : 743** - In a nuclear power plant based on pressurised-water reactor, which substance is used both as the moderator and as the heat transfer medium?

**Options**:

1) air

2) hydrogen

3) nitrogen

4) water**Correct Answer**: water**QID : 744** - In a stationary wave in a stretched string fixed at both ends the first anti-node is formed at x = __________. ('λ' is the wavelength of the stationary wave)

**Options**:

1) λ/4

2) λ/2

3) λ

4) 2λ**Correct Answer**: λ/4**QID : 745 **- In a uniform magnetic field 'B', a charge 'q' of mass 'm' executes a circular orbit in a plane normal to 'B'. Its frequency of uniform circular motion is called the cyclotron frequency which is equal to?

**Options**:

1) qB/(2πm)

2) 2qB/(πm)

3) 2π/qB

4) pπ/(2qB)**Correct Answer**: qB/(2πm)**QID : 746** - In Einstein's mass-energy equivalence relation E = mc2, 'c' stands for?

**Options**:

1) Planck constant

2) elementary charge

3) atomic mass constant

4) speed of light**Correct Answer**: speed of light**QID : 747** - In equilibrium, the total energy is equally distributed in all possible energy modes for a molecule, with each mode having an average energy equal to?

**Options**:

1) kBT/2

2) kBT

3) 2kBT

4) kBT/4**Correct Answer**: kBT/2**QID : 748** - In Rutherford's gold foil experiment which of the following were directed towards the gold foil?

**Options**:

1) β-particles

2) γ-particles

3) electrons

4) α-particles**Correct Answer**: α-particles

**QID : 749 **- In simple harmonic motion, the particle velocity lags behind the displacement by a phase angle of __________.

**Options**:

1) π/2

2) -π/4

3) π

4) -π**Correct Answer**: π/2**QID : 750** - In the formula, 1/λ = R(1/52 - 1/n2) which represents the Pfund spectral series for hydrogen, 'R' is _____________ constant.

**Options:**

1) Planck

2) Bohr

3) Thomson

4) Rydberg**Correct Answer**: Rydberg

**QID : 751** -In the relation from Kinetic theory of gases, PV = (1/3)Nmv2, if 'N' is number of particles then 'm' stands for?

**Options:**

1) Molecular mass

2) Mass of the gas

3) Mass of the particle

4) Number of moles of the gas**Correct Answer**: Mass of the particle

**QID : 752** - In the simple harmonic motion x = √2 sin(ωt – π/4), the phase constant can be shown as?

**Options:**

1) √2

2) 2π/ω

3) ωt

4) 7π/4**Correct Answer**: 7π/4**QID : 753 -** In which Thermodynamic process is temperature constant?

**Options**:

1) Isobaric

2) Isochoric

3) Adiabatic

4) Isothermal**Correct Answer**: Isothermal

**QID : 754** - Inductive reactance is equal to?

**Options**:

1) 1/(ωL)

2) ω/L

3) L/ω

4) ωL**Correct Answer**: ωL**QID : 755 **- Louis de Broglie argued that the electron in its circular orbit must be seen as a particle wave, whose wavelength is equal to _______ , where 'p' is the magnitude of the electron’s momentum and 'h' is Planck's constant.

**Options**:

1) hp

2) p/h

3) h/p2

4) h/p**Correct Answer**: h/p**QID : 756 **- One end of a cylindrical pipe of cross-section 6.6 cm² has 14 holes each of radius 1 mm. If water is flowing in the pipe at 1 m/min then what is the speed (in m/s) of efflux through the holes?

**Options**:

1) 0.25

2) 0.125

3) 0.625

4) 0.5**Correct Answer**: 0.25**QID : 757 **- What does STP means?

**Options**:

1) 0 degree Celsius temperature and 1 pascal pressure.

2) 0 kelvin temperature and 1 atm pressure.

3) 0 kelvin temperature and 1 pascal pressure.

4) 0 degree Celsius and 1 atm pressure.**Correct Answer**: 0 degree Celsius and 1 atm pressure.**QID : 758 **- Tensile stress on a metal wire of radius 1 mm is 10,000 N/m². How much is the restoring force developed in it (in N)?

**Options**:

1) 3.14 x 10²

2) 3.14 x 10-2

3) 3.14 x 10-4

4) 3.14 x 104**Correct Answer**: 3.14 x 10-2

**QID : 759 **- The _____________ of thermodynamics states that if two thermodynamic systems are each in thermal equilibrium with a third system separately are in thermal equilibrium with each other.

**Options**:

1) Zeroth Law

2) First Law

3) Second Law (Clausius statement)

4) Second Law (Kelvin-Planck statement)**Correct Answer**: Zeroth Law

**QID : 760 **- The _______________ Law is an equation that describes the magnetic field created by a current-carrying wire, and allows you to calculate its strength at various points.

**Options**:

1) Ampere's

2) Lorentz's

3) Biot-Savart's

4) Kirchhoff’s**Correct Answer**: Biot-Savart's

**QID : 761 **- The ______________________ is a device to measure the flow speed of incompressible fluid.

**Options**:

1) Alti-meter

2) Baro-meter

3) Venturi-meter

4) Hydro-meter**Correct Answer**: Venturi-meter

**QID : 762 **- The acceleration of an object moving with speed 'v' in a circle of radius 'R' has a magnitude given by which formula?

**Options**:

1) a = v² x R

2) a = v/R²

3) a = v x R²

4) a = v²/R**Correct Answer**: a = v²/R

**QID : 763 - **The amount of scattering of light is inversely proportional to the fourth power of its wavelength. This is known as ____________ scattering.

**Options**:

1) Maxwell

2) Hertz

3) Huygens

4) Rayleigh**Correct Answer**: Rayleigh

**QID : 764 **- The capacity of a parallel plate capacitor where 'A' is the area of each plate, 'd' the separation between them and with vacuum between the plates is given as?

**Options**:

1) C = ?oAd

2) C = ?o/(Ad)

3) C = ?oA/d

4) C = ?oA/d2**Correct Answer**: C = ?oA/d**QID : 765 **- The charge on an electron is ___________x 10-19 C.

**Options**:

1) 2.4

2) 3.2

3) 1.6

4) 4.8**Correct Answer**: 1.6**QID : 766 **- The current in the inductor __________________.

**Options**:

1) lags the voltage by π/2

2) leads the voltage by π/2

3) lags the voltage by π

4) leads the voltage by π**Correct Answer**: lags the voltage by π/2

**QID : 767 **- The expression eτ/m, where 'τ' is the relaxation time, 'e' is charge and 'm' is mass of an electron is equal to the ______________.

**Options**:

1) conductivity of the material

2) mobility of the electrons

3) resistivity of the material

4) permittivity of the material**Correct Answer**: mobility of the electrons

**QID : 768 **- The fringe pattern observed in Young's Experiment to produce interference pattern will strictly be a?

**Options**:

1) Hyperbola

2) Ellipse

3) Circular

4) Parabola**Correct Answer**: Hyperbola

**QID : 769 **- The human eye can detect electromagnetic radiation in the range of wavelength _______________.

**Options**:

1) 800 nm to 1050 nm

2) 400 nm to 750 nm

3) 1200 nm to 1550 nm

4) 1600 nm to 1950 nm**Correct Answer**: 400 nm to 750 nm**QID : 770** - The hydraulic lift is based on which of the following?

**Options**:

1) Bernoulli's principle

2) Pascal's Law

3) Archimedes' principle

4) Boyle's law**Correct Answer**: Pascal's Law**QID : 771** - Which of the following is the ice point of water in the Fahrenheit scale?

**Options**:

1) 212o F

2) 0o F

3) 273o F

4) 32o F**Correct Answer**: 32o F**QID : 772** - The mass of the hydrogen isotope, tritium is about the same as the masses of?

**Options**:

1) 3 electrons

2) 3 protons + 3 neutrons

3) 1 proton + 3 neutrons

4) 1 proton + 2 neutrons

**Correct Answer**: 1 proton + 2 neutrons**QID : 773 **- The mathematical difference between molar specific heat capacities of an ideal gas at constant pressure and volume is equal to which of the following?

**Options**:

1) Carnot constant

2) Boltzmann constant

3) Universal gas constant

4) Rydberg constant**Correct Answer**: Universal gas constant**QID : 774 **- The molar specific heat at constant volume for monoatomic gas is which of the following?

**Options**:

1) 7R/2

2) 9R/2

3) 3R/2

4) 5R/2**Correct Answer**: 3R/2

**QID : 775 - **The nucleus of which of the following atoms whose atomic mass numbers 'A' are given in the options would have the highest binding energy per nucleon?

**Options**:

1) 200

2) 100

3) 5

4) 20**Correct Answer**: 100

**QID : 776 **- The period 'T' a pendulum of string length 'L', bob of mass 'm' and moment of inertia 'I' is given by _________________.

**Options:**

1) T = 2π √(IL/mg)

2) T = 2π √(I/mgL)

3) T = 2π √(mgL/I)

4) T = 2π √(mg/IL)**Correct Answer**: T = 2π √(I/mgL)**QID : 777 **- The phenomenon of rainbow is due to the combined effect of all of the following properties of light except ____________.

**Options**:

1) dispersion

2) refraction

3) reflection

4) polarization**Correct Answer**: polarization**QID : 778** - The power loss in a conductor of resistance 'R' across which a potential difference of 'V' is equal to which of the following?

**Options:**

1) V/R2

2) V2R

3) VR2

4) V2/R**Correct Answer**: V2/R**QID : 779 **- Which of the following is the product of moment of inertia and angular velocity?

**Options**:

1) Angular momentum

2) Power

3) Torque

4) Work**Correct Answer**: Angular momentum

**QID : 780 -** The radius of orbit of the electron in a hydrogen atom is equal to? (?o is permittivity of free space, 'e' is charge and 'm' is mass of an electron)

**Options**:

1) e/(4π?omv2)

2) mv2e2/(4π?o)

3) mv2e/(4π?o)

4) e2/(4π?omv2)**Correct Answer**: e2/(4π?omv2)**QID : 781** - The refractive index of denser medium 2 with respect to rarer medium 1 will be ____________ (where 'C' is the measure of the critical angle).

**Options**:

1) n12 = 1/sinC

2) n21 = 1/sinC

3) n12 = sinC

4) n12 = 1/(-sinC)**Correct Answer**: n12 = 1/sinC**QID : 782 **- The speed 'c' of electromagnetic wave in vacuum is equal to? (where μo and ?o are free space permeability and permittivity constants)

**Options**:

1) 1/√(µo?o)

2) 1/(µo?o)

3) µo?o

4) (µo?o)2**Correct Answer**: 1/√(µo?o)**QID : 783 -** The speed 'v' of transverse waves on a stretched string of linear mass density 'μ' and tension 'T' is equal to?

**Options**:

1) √(µ/T)

2) √(T/µ)

3) (T/µ)2

4) (µ/T)2**Correct Answer**: √(T/µ)

**QID : 784 -** The statement, "The liquid pressure is the same at all points at the same horizontal level irrespective of cross sectional area or base area or the shape of the container" represents which of the following?

**Options**:

1) Anomalous behaviour of water

2) The hydrostatic paradox

3) Algol paradox

4) Archimedes' principle**Correct Answer**: The hydrostatic paradox**QID : 785** - Electric flux through a closed surface 'S' enclosing a charge 'q' is equal to ______________. (?o is permittivity of free space)

**Options**:

1) q?o

2) q2?o

3) ?o/q

4) q/?o**Correct Answer**: q/?o**QID : 786 -** There is a fundamental limit on the efficiency of a heat engine set by an independent principle of nature called the ____________Law of Thermodynamics.

**Options:**

1) Zeroth

2) First

3) Third

4) Second**Correct Answer**: Second**QID : 787 -** Three quantities are needed to specify the magnetic field of the earth on its surface. Which of the following is not needed?

**Options:**

1) the vertical component

2) the horizontal component

3) the magnetic declination

4) the magnetic dip**Correct Answer** the vertical component

**QID : 788 **- Water at 4 oC has maximum _____________.

**Options:**

1) volume

2) viscosity

3) compressibility

4) density**Correct Answer** density

**QID : 789 **- What is the magnifying power of a compound microscope whose eyepiece has a focal length of 10 cm and the magnifying power of objective is 4? (Use least distance of distinct vision as 25 cm)

**Options**:

1) 3.5

2) 14

3) 8

4) 16**Correct Answer**: 14**QID : 790 **- What is the Moment of Inertia of a thin circular ring of mass 'M' and radius 'R' about its diameter?

**Options**:

1) MR²/4

2) MR²/3

3) MR²/2

4) MR²/6**Correct Answer**: MR²/2**QID : 791 -** What would be the acceleration (in m/s²) due to gravity on a planet whose mass is 1/7th the mass of earth and radius, half the radius of earth?

**Options**:

1) 5.6

2) 4.9

3) 4.2

4) 3.5**Correct Answer**: 5.6**QID : 792 **- What would be the frequency (in Hz) of the beats when two sounds of frequencies 256 Hz and 260 Hz superimpose?

**Options**:

1) 8

2) 2

3) 16

4) 4**Correct Answer**: 4**QID : 793** - When temperature is held constant, the pressure and volume of a quantity of gas are related as PV = constant. This relationship is known as?

**Options**:

1) Charles’ law

2) Boyle’s law

3) Combined Gas Law

4) Gay-Lussac's Law**Correct Answer**: Boyle’s law**QID : 794 **- When the transistor is used in the cut-off or saturation state, it acts as?

**Options**:

1) An amplifier

2) Zener diode

3) A switch

4) An AND gate**Correct Answer**: A switch

**QID : 795 **- Which formula represents Newton's Law of Gravitation?

**Options**:

1) F= Gm1m2/r (G is gravitational constant)

2) F= Gm1m2/r² (G is gravitational constant)

3) F= gm1m2/r² (g is acceleration due to gravity)

4) F= gm1m2/r (g is acceleration due to gravity)**Correct Answer**: F= Gm1m2/r² (G is gravitational constant)**QID : 796** -

**Options:**

1) AND

2) NAND

3) NOR

4) OR**Correct Answer**r: OR**QID : 797** - Which of the following is a periodic function if 'ω' is a constant and 't' represents time?

**Options:**

1) log (ωt)

2) e–ωt

3) 2?√(1/ωt)

4) sin ωt + cos 2 ωt + sin 4 ωt**Correct Answer**: sin ωt + cos 2 ωt + sin 4 ωt**QID : 798 **- Which of the following is false about Electrostatic field lines?

**Options:**

1) Field lines start from positive charges and end at negative charges.

2) If there is a single positive charge field lines will end at infinity.

3) Two field lines can never cross each other.

4) Electrostatic field lines form closed loops.**Correct Answer**: Electrostatic field lines form closed loops.**QID : 799 **- Which of the following statements is consistent with the Doppler effect?

**Options:**

1) As the source of sound moves towards the listener the pitch of the sound appears to be higher.

2) As the source of sound moves towards the listener the pitch of the sound appears to be lower.

3) As the source of sound moves away from the listener the pitch of the sound appears to be higher.

4) As the listener moves towards the source of sound the pitch of the sound appears to be lower.**Correct Answer**: As the source of sound moves towards the listener the pitch of the sound appears to be higher.**QID : 800 -** Zener diode is fabricated by __________________ of the junction.

**Options:**

1) lightly doping both p and n-sides

2) heavily doping both p and n-sides

3) heavily doping p-side and lightly doping n-side

4) lightly doping p-side and heavily doping n-side**Correct Answer**heavily doping both p and n-sides