Practice Questions

Q20. In the truth table of the above circuit the value of X and Y are : (1) 0,0 (2) 1,1 (3) 1,0 (4) 0,1

Q20.Given below are two statements: one is labelled as Assertion(A) and the other is labelled as Reason (R). Assertion (A) : In Vernier calliper if positive zero error exists, then while taking measurements, the reading taken will be more than the actual reading. Reason (R) : The zero error in Vernier Calliper might have happened due to manufacturing defect or due to rough handling. In the light of the above statements, choose the correct answer from the options given below : (1) Both (A) and (R) are correct and (R) is the (2) Both (A) and (R) are correct but (R) is not the correct explanation of (A) correct explanation of (A) (3) (A) is true but (R) is false (4) (A) is false but (R) is true

Q20.The diameter of a sphere is measured using a vernier caliper whose 9 divisions of main scale are equal to 10 divisions of vernier scale. The shortest division on the main scale is equal to 1 mm . The main scale reading is 2 cm and second division of vernier scale coincides with a division on main scale. If mass of the sphere is 8.635 g, the density of the sphere is: (1) 2.0 g/cm3 (2) 1.7 g/cm3 (3) 2.2 g/cm3 (4) 2.5 g/cm3 JEE Main 2024 (08 Apr Shift 1) JEE Main Previous Year Paper −−−

Q20.Following gates section is connected in a complete suitable circuit. For which of the following combination, bulb will glow (ON) : (1) A = 0, B = 0, C = 0, D = 1 (2) A = 0, B = 1, C = 1, D = 1 (3) A = 1, B = 0, C = 0, D = 0 (4) A = 1, B = 1, C = 1, D = 0

Q20.A vernier callipers has 20 divisions on the vernier scale, which coincides with 19th division on the main scale. The least count of the instrument is 0.1 mm. One main scale division is equal to _____ mm . (1) 0.5 (2) 2 (3) 5 (4) 1

Q20.The truth table for this given circuit is: JEE Main 2024 (29 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q20.The value of net resistance of the network as shown in the given figure is : (1) 6Ω (2) (5/2)Ω (3) (15/4)Ω (4) (30/11)Ω

Q20.A Zener diode of breakdown voltage 10 V is used as a voltage regulator as shown in the figure. The current through the Zener diode is (1) 50 mA (2) 0 (3) 30 mA (4) 20 mA

Q20.The measured value of the length of a simple pendulum is 20 cm with 2 mm accuracy. The time for 50 oscillations was measured to be 40 seconds with 1 second resolution. From these measurements, the accuracy in the measurement of acceleration due to gravity is 𝑁%. The value of 𝑁 is: (1) 4 (2) 8 (3) 6 (4) 5

Q20.If 50 Vernier divisions are equal to 49 main scale divisions of a travelling microscope and one smallest reading of main scale is 0 . 5 mm the Vernier constant of travelling microscope is: (1) 0 . 1 mm (2) 0 . 1 cm (3) 0 . 01 cm (4) 0 . 01 mm → →

Q20.Identify the physical quantity that cannot be measured using spherometer : (1) Radius of curvature of concave surface (2) Specific rotation of liquids (3) Thickness of thin plates (4) Radius of curvature of convex surface

Q20.Conductivity of a photodiode starts changing only if the wavelength of incident light is less than 660 nm . X The band gap of photodiode is found to be eV . The value of X is: 8 (Given h = 6 . 6 × 10-34 J s, e = 1 . 6 × 10-19 C) (1) 15 (2) 11 (3) 13 (4) 21

Q20.There are 100 divisions on the circular scale of a screw gauge of pitch 1 mm . With no measuring quantity in between the jaws, the zero of the circular scale lies 5 divisions below the reference line. The diameter of a wire is then measured using this screw gauge. It is found that 4 linear scale divisions are clearly visible while 60 divisions on circular scale coincide with the reference line. The diameter of the wire is : (1) 3.35 mm (2) 4.65 mm (3) 4.55 mm (4) 4.60 mm

Q20.While measuring diameter of wire using screw gauge the following readings were noted. Main scale reading is 1 mm and circular scale reading is equal to 42 divisions. Pitch of screw gauge is 1 mm and it has 100 divisions on circular scale. The diameter of the wire is x mm . The value of x is : 50 (1) 21 (2) 142 (3) 71 (4) 42

Q21.For three vectors →A = (−x^i −6^j −2^k), →B = (−^i + 4^j + 3^k) and →C = (−8^i −^j + 3^k), if →A ⋅(→B × →C) = 0, then value of x is _________

Q21.A body of mass M thrown horizontally with velocity v from the top of the tower of height H touches the ground at a distance of 100 m from the foot of the tower. A body of mass 2M thrown at a velocity 2v from the top of the tower of height 4H will touch the ground at a distance of _____ m . JEE Main 2024 (08 Apr Shift 2) JEE Main Previous Year Paper

Q21.A particle moves in a straight line so that its displacement x at any time t is given by x2 = 1 + t2 . Its acceleration at any time t is x−n where n = ___________

Q21.The resultant of two vectors →A and →B is perpendicular to →A and its magnitude is half that of →B. The angle between vectors →A and →B is ______ ∘.

Q21.A particle is moving in one dimension (along 𝑥 axis) under the action of a variable force. It's initial position was 16 m right of origin. The variation of its position 𝑥 with time 𝑡 is given as 𝑥= – 3𝑡3 + 18𝑡2 + 16𝑡, where 𝑥 is in m and 𝑡 is in s . The velocity of the particle when its acceleration becomes zero is _________ m s-1 . JEE Main 2024 (01 Feb Shift 1) JEE Main Previous Year Paper

Q21.A particle initially at rest starts moving from reference point 𝑥= 0 along 𝑥-axis, with velocity 𝑣 that varies as 𝑣= 4√𝑥 m s-1. The acceleration of the particle is _____ m s-2.

Q21.The displacement and the increase in the velocity of a moving particle in the time interval of t to (t + 1) s are 125 m and 50 m s−1 , respectively. The distance travelled by the particle in (t + 2)th s is ___________ m .

Q21.A body starts falling freely from height 𝐻 hits an inclined plane in its path at height ℎ. As a result of this perfectly elastic impact, the direction of the velocity of the body becomes horizontal. The value of 𝐻 for which ℎ the body will take the maximum time to reach the ground is _____.

Q21.A ball rolls off the top of a stairway with horizontal velocity u. The steps are 0. 1 m high and 0. 1 m wide. The minimum velocity u with which that ball just hits the step 5 of the stairway will be √x m s−1 , where x = _______ [use g = 10 m s−2 ].

Q21.A vector has magnitude same as that of 𝐴= 3 ^j + 4 ^j and is parallel to 𝐵= 4 ^i + 3 ^j. The 𝑥 and 𝑦 components of this vector in first quadrant are 𝑥 and 3 respectively where x = ____.

Q21.A bus moving along a straight highway with speed of 72 km/h is brought to halt within 4s after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is _____m.