ECAT Physics MCQs — Download ECAT Physics Papers

Q1 If the least count of a measuring device is 1 kg, then the number of significant figures in 80000 kg or 8.0000 × 10⁴ kg is:

• A) One
• B) Two
• C) Three
• D) Five

Q2 4.2 + 3.68 + 7.436 = _____ (up to appropriate precision):

• A) 15.3
• B) 15.31
• C) 15.316
• D) 15.4

Q3 9.6 × 12.3 = _____ (according to the rule of significant figures or accuracy):

• A) 1.08 × 10²
• B) 1.10 × 10²
• C) 1.1 × 10²
• D) 1.2 × 10²

Q1 1 femto = _____ atto:

• A) 10
• B) 10²
• C) 10³
• D) 10⁴

Q2 Which one is the correct option for the unit of torque?

• A) n·m
• B) n·M
• C) Nm
• D) N·m

Q3 The number of main frontiers of fundamental science at present is:

• A) Four
• B) Two
• C) Three
• D) Eight

Q4 The information from the far side of the universe is gathered by:

• A) Terrestrial telescope
• B) Galilean telescope
• C) Astronomical telescope
• D) Radio telescope

Q5 Computer chips are made of:

• A) Iron
• B) Metalloid silicon
• C) Silver
• D) Gold

Q1 The Big Bang was proved by _____ waves.

• A) X-rays
• B) Ultra-violet
• C) Radio
• D) γ-rays

Q2 Which of these is NOT an inter-disciplinary area of physics?

• A) Bio-physics
• B) Astrophysics
• C) Physics of Music
• D) Physics of solids

Q3 The Big Bang occurred:

• A) 20 million years ago
• B) 2 billion years ago
• C) 10 billion years ago
• D) 20 billion years ago

Q4 The equation which gives the relation between the basic and derived units is called:

• A) Dimensional equation
• B) Fundamental equation
• C) Homogeneity equation
• D) Transfer equation

Q5 One metre is equal to how many wavelengths in vacuum of the orange-red radiation emitted by the Kr-86 atom?

• A) 1,650,763.73
• B) 1,450,763.63
• C) 1,250,763.73
• D) 1,420,763.63

Q1 Light year is a unit of:

• A) Time
• B) Length
• C) Both (A) and (B)
• D) Mass

Q2 The unit of amount of substance at the micro level is:

• A) kg
• B) mole
• C) g
• D) Mg

Q3 The standard metre rod is an alloy made from _____ platinum and _____ iridium.

• A) 10%, 90%
• B) 90%, 10%
• C) 20%, 80%
• D) 80%, 20%

Q4 1 kg mass (concentrated form of energy) means energy equal to:

• A) 9 × 10¹² J
• B) 9 × 10¹⁶ J
• C) 9 × 10¹³ J
• D) 9 × 10¹⁴ J

Q5 The time duration of 9,192,631,770 vibrations made by the outermost electron of a Cs-133 atom is:

• A) 0.5 sec
• B) 0.8 sec
• C) 0.9 sec
• D) 1 sec

Q6 The atomic clock uses the _____ isotope.

• A) Cesium
• B) Krypton
• C) Carbon
• D) Helium

Q7 Wave number has the same unit as that of:

• A) 1/λ
• B) 1/f
• C) 1/c
• D) λ

Q8 Which of the following pairs does NOT have the same units?

• A) Torque and angular momentum
• B) Young’s modulus and pressure
• C) Torque and work
• D) Work and energy

Q1 The numerical value of the magnitude of a physical quantity is:

• A) Directly proportional to magnitude of unit
• B) Inversely proportional to magnitude of unit
• C) Independent of system of units
• D) Invariable

Q2 Measurement of a physical quantity requires:

• A) A standard
• B) Measurement procedure
• C) Measurement unit
• D) All of these

Q3 N/kg is a unit of:

• A) Force
• B) Velocity
• C) Acceleration
• D) Mass

Q4 Radian is the supplementary unit of:

• A) Solid angle
• B) Three-dimensional angle
• C) Space angle
• D) Plane angle

Q5 Solid angle for a complete sphere in steradian is:

• A) π
• B) 2π
• C) 3π
• D) 4π

Q1 If units of length, mass and time are each doubled, the unit of work done is increased by _____ times.

• A) 2
• B) 8
• C) 6
• D) 4

Q2 A platinum black-body radiator is used for the definition of:

• A) Kelvin
• B) Candela
• C) Current
• D) Mole

Q3 Which of the following is a derived quantity?

• A) Electric current
• B) Luminous intensity
• C) Torque
• D) Mass

Q4 1 Fermi = _____ Å (Angstrom):

• A) 10⁵
• B) 10^-3
• C) 10^-6
• D) 10^-5

Q5 1 km² = _____ :

• A) 1 × 10³ m²
• B) 1 × 10² m²
• C) 1 × 10⁴ m²
• D) 1 × 10⁶ m²

Q1 Error due to repeated measurement is _____ error.

• A) Systematic
• B) General
• C) Random
• D) Common

Q2 Which error is reduced by taking the average of measured values?

• A) Systematic error
• B) Random error
• C) General error
• D) Zero error

Q3 Systematic error influences:

• A) First reading only
• B) 2nd reading only
• C) Last reading only
• D) All readings (measurements) of a quantity equally

Q4 Maximum possible error in the reading of an instrument is:

• A) Half its least count
• B) Quarter of its least count
• C) Equal to its least count
• D) Double of its least count

Q1 If the length of a rod lies between 13.25 cm and 13.35 cm, then the maximum uncertainty is:

• A) ±0.01 cm
• B) ±0.02 cm
• C) ±0.005 cm
• D) ±0.03 cm

Q2 Least count is equal to:

• A) Fractional uncertainty
• B) Maximum uncertainty
• C) Percentage uncertainty
• D) Absolute uncertainty

Q3 Least count of a metre rod:

• A) Can be zero
• B) Is 1 cm
• C) Is 0.1 mm
• D) Can never be zero

Q4 Number of significant figures in 0.0040720010 × 10³ are:

• A) 2
• B) 4
• C) 6
• D) 8

Q5 If x = at + bt², where x is in metres and t is in hours, then units of b will be:

• A) metre
• B) metre/hour²
• C) metre/hour
• D) metre²/hour

Q6 Four colours required for colour printing are:

• A) Blue, Yellow, Green, Orange
• B) Cyan, Green, Yellow, Orange
• C) Cyan, Magenta, Yellow, Black
• D) Violet, Indigo, Blue, Green

Q1 Less percentage or fractional uncertainty means:

• A) High accuracy
• B) High precision
• C) Both (A) and (B)
• D) High accuracy and low precision

Q2 If x₁ = 2.5 ± 0.1 cm and x₂ = 1.3 ± 0.1 cm, then x₁ – x₂ =

• A) 1.2 ± 0 cm
• B) 1.2 ± 0.1 cm
• C) 1.2 ± 0.2 cm
• D) 1.2 ± 0.3 cm

Q3 If % errors in V and I are 6% and 2% respectively, then percentage uncertainty in R according to Ohm’s law is:

• A) 2%
• B) 4%
• C) 8%
• D) 1%

Q4 A wire when heated shows a 2% increase in radius. The increase in cross-sectional area is:

• A) 4%
• B) 2%
• C) 8%
• D) 3%

Q5 If % errors in moment of inertia and angular velocity are 2% and 4% respectively, then % error in rotational K.E is:

• A) 2%
• B) 4%
• C) 10%
• D) 8%

Q6 For a cylinder, if L = 1.0 ± 0.1 cm and r = 1.0 ± 0.1 cm, then % uncertainty in Volume =

• A) 10%
• B) 20%
• C) 30%
• D) 40%

Q1 If diameters of a wire are measured as 1.20, 1.22, 1.21 mm, then uncertainty in the average value will be:

• A) 0.01 mm
• B) 0.02 mm
• C) 0.1 mm
• D) 0.2 mm

Q2 To reduce uncertainty in a timing experiment:

• A) Least count should be increased
• B) Number of vibrations should be increased
• C) Number of vibrations should be decreased
• D) Number of vibrations should be kept constant

Q3 Dimensions are treated as:

• A) Algebraic quantities
• B) Trigonometric quantities
• C) Logarithmic quantities
• D) Exponential quantities

Q1 The dimensions of ½at² are the same as that of:

• A) Length
• B) Velocity
• C) Force
• D) Acceleration

Q2 The dimensions of 1/√(μ₀ε₀) are the same as that of:

• A) Distance
• B) Velocity
• C) Capacitance
• D) Time

Q3 The dimensions of coefficient of viscosity are:

• A) MLT
• B) MLT^-1
• C) ML^-1T
• D) ML^-1T^-1

Q4 The dimensional formula for the gravitational constant G is:

• A) ML²T^-3
• B) M^-1L³T^-2
• C) ML²T^-2
• D) M^-1L²T^-3

Q5 Which of the following quantities is dimensionless?

• A) Tensile strain
• B) Tensile stress
• C) Young’s modulus
• D) Planck’s constant

Q6 Dimensions of plane angle are:

• A) T
• B) L
• C) θ
• D) Nil

Q1 Which of these depends upon the measuring device?

• A) Fractional uncertainty
• B) Percentage uncertainty
• C) Both (A) and (B)
• D) Absolute uncertainty

Q2 The dimensions of L/R are the same as that of:

• A) Length
• B) Velocity
• C) Time
• D) Distance

Q3 The fundamental quantity which has the same power in the dimensional formula of surface tension and viscosity is:

• A) Mass
• B) Length
• C) Time
• D) All have same powers

Q4 For a power-factor formula like V = 4πr³/3, % age uncertainty in V =

• A) (% uncertainty in r)³
• B) (% uncertainty in r) / 3
• C) 3 × % uncertainty in r
• D) % uncertainty in r³