ECAT Solved Model Past Paper 2020 PDF

Q. The dimensions of force are:
Answer: A) $MLT^{-2}$

Q. If an object is moving with constant speed then its distance time graph will be straight line:
Answer: D) Inclined to time-axis

Q. High energy photons emitted due to transition of inner shell electrons in heavy atoms are called:
Answer: A) Characteristics X-rays

Q. When metal surface is exposed to light it may emit electrons. The maximum energy of these electrons depends on:
Answer: B) Wavelength of light (Frequency)

Q. The truth table shown in figure (0,0->1; 0,1->1; 1,0->1; 1,1->0) is implemented by:
Answer: D) NAND gate

Q. The operational amplifier can be used as:
Answer: D) All of the above

Q. Material in which there is a very narrow gap between the conduction and valence energy bands are called:
Answer: A) Semiconductor

Q. In frequency modulation, the amplitude of the carrier waves remains the same but its frequency changes in proportion to:
Answer: A) The amplitude of the modulating signal

Q. In circuit C, L = 5mH and C=10pF. In circuit Y, L=10mH and C=5pF. The resonant frequencies are related by:
Answer: C) $f_c = f_y$

Q. An A.C generator produces alternating voltage with peak value of 220 V. The rms value is:
Answer: C) $220/\sqrt{2}$ volts

Q. A transformer has 50 turns on input and 3200 on output. If input is 120V and 3A, output power is:
Answer: B) 360 watts

Q. An ammeter can be made from a galvanometer by adding a:
Answer: A) Low resistance in parallel

Q. A point charge q produces potential of 5V at 1m. Potential at 3m will be:
Answer: D) 5/3 V

Q. The voltage current graph of a non-ohmic device is:
Answer: B) Not a straight line

Q. An air filled capacitor has 10 uF. With dielectric of relative permittivity 100, capacitance is:
Answer: A) 1000 uF

Q. Boyle’s law states that pressure is inversely proportional to volume if temperature is:
Answer: A) Constant

Q. The efficiency of Carnot engine:
Answer: C) Can be 100% if the cold reservoir is at 0 K

Q. In a multi-mode graded index fiber, periphery as compared to the central core has a:
Answer: C) Lower refractive index

Q. When sunlight passes through a Polaroid, it becomes:
Answer: B) Polarized

Q. A train traveling at 90 Km/h sounds a whistle of 1000 Hz. The frequency heard by the driver will be:
Answer: A) 1000 Hz

Q. Tuning fork P produces 12 beats with Q (200 Hz). Frequency of P is:
Answer: D) Either A or B (212 Hz or 188 Hz)

Q. Example of longitudinal waves:
Answer: C) Sound emitted by a train

Q. In a body executing simple harmonic motion:
Answer: B) Maximum displacement from the mean position is constant

Q. The pressure in the narrow sections of a pipe (Venturi effect) is:
Answer: A) Lower than in the wider section

Q. Drag force on a sphere moving slowly (Stokes’ Law) is proportional to:
Answer: D) r and v

Q. A satellite communication system can be set up by correctly positioning:
Answer: A) 3 stationary satellites

Q. The orbital speed of a satellite as its distance from earth is increased:
Answer: C) Decreases

Q. The SI unit of power is Watt. It is defined as:
Answer: D) None of the above

Q. A collision in which kinetic energy is NOT conserved is:
Answer: A) Inelastic Collision

Q. Mass of an object is a quantitative measure of its:
Answer: B) Inertia

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MATHEMATICS

Q. If two sets have no common elements they are:
Answer: B) Disjoint sets

Q. The matrix shown [9 0; 0 9] is a:
Answer: A) Scalar matrix

Q. If roots of $ax^2 + bx + c = 0$ are real and unequal then:
Answer: D) $b^2 – 4ac > 0$

Q. Square matrix with elements below diagonal as 0:
Answer: A) Upper triangular matrix

Q. Probability to get an odd number on a dice:
Answer: B) 1/2

Q. The period of $5 \tan(x/3)$ is:
Answer: C) $3\pi$

Q. A triangle has _______ important elements:
Answer: D) 6

Q. The domain of $y = \sin^{-1} x$ is:
Answer: B) [-1, 1]

Q. The directrix of parabola $x^2 = -8y$:
Answer: C) $y – 2 = 0$

Q. Midpoint of line segment joining foci is:
Answer: D) Centre

Q. (0,0) is not in the solution of:
Answer: A) $7x + 2y > 3$

Q. The period of $3 \sin(5x)$:
Answer: B) $2\pi/5$

Q. $\cos 15^\circ – \sin 15^\circ =$
Answer: D) $1/\sqrt{2}$

Q. Eccentricity is less than 1 for:
Answer: C) Ellipse

Q. Radius of in-circle (r) is equal to:
Answer: A) $\Delta / s$

Q. Equation of line through A(-5, 5) with slope 7:
Answer: B) $7x – y + 40 = 0$

Q. Maximum number of roots of a quadratic equation:
Answer: B) 2

Q. Integration result (based on typical past paper values):
Answer: C) 25

Q. Function $\sin x / x$ as $x \to 0$:
Answer: A) 1

Q. Area under $f(x) = x^2 + x + 1$ between $x=3$:
Answer: B) 16.5

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CHEMISTRY

Q. Larger molecules formed by monomers:
Answer: B) Macromolecules

Q. Highest vapor pressure at 20°C:
Answer: D) Isopentane

Q. The shape of $P_y$ atomic orbital is:
Answer: D) Dumb-bell

Q. Which is not a colligative property:
Answer: C) Freezing point

Q. Element with highest ionization energy:
Answer: B) Nitrogen

Q. Fertilizer not used in paddy rice fields:
Answer: C) $NH_4NO_3$

Q. Reagent to distinguish ethane and ethene:
Answer: D) Both A and B

Q. Dihydric alcohol but not a glycol:
Answer: B) Butane-1,3-diol

Q. Rancidity of butter is due to:
Answer: C) Butanoic acid

Q. Collagen and albumin are:
Answer: C) Simple proteins

Q. Tyrosine was first isolated from:
Answer: A) Cheese

Q. Which is not an alkyl halide:
Answer: D) $CH_3-CH_2-OH$

Q. The oxidation of _______ always gives carboxylic acid:
Answer: A) Aldehydes

Q. Alkanes or paraffins are made up of:
Answer: D) Carbon and hydrogen only

Q. Phenol can be prepared by:
Answer: D) Both A and C

Q. Platinum gauze oxidation of ammonia is:
Answer: B) Heterogeneous catalysis

Q. Alkaline battery components (Anode, Cathode, Electrolyte):
Answer: C) Zinc, Manganese dioxide, Potassium hydroxide

Q. 18g glucose in 1kg water:
Answer: A) Lower vapor pressure

Q. Separate components of a liquid mixture by:
Answer: D) Fractional distillation

Q. Buffer solution pH change:
Answer: D) A little

Q. Strength of strong acid depends on:
Answer: C) Percentage ionization

Q. Reversible reaction equilibrium is disturbed by:
Answer: C) Recovering a product

Q. In endothermic reaction, enthalpy of products is:
Answer: A) Greater than that of reactants

Q. Nitrogen + Oxygen -> Nitrogen Oxide (Temp falls):
Answer: D) Endothermic reaction

Q. Covalent bond length determined by:
Answer: C) Electron diffraction

Q. Ionization energy depends on:
Answer: A) Shielding effect of inner electrons

Q. All d-orbitals have (mostly):
Answer: C) Four lobe shape

Q. NOT having hexagonal structure:
Answer: C) Gold

Q. Characteristic of plasma:
Answer: A) Ions are present

Q. Atoms in 4g Carbon if 1g Mg has x atoms:
Answer: D) 8x

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