Practice Questions

Q29.The refractive index of a transparent liquid filled in an equilateral hollow prism is √2. The angle of minimum deviation for the liquid will be _______ °.

Q29.Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R Assertion A: Photodiodes are used in forward bias usually for measuring the light intensity. Reason R: For a p −n junction diode, at applied voltage V the current in the forward bias is more than the current in the reverse bias for |Vz| > ±V ≥|V0| where V0 is the threshold voltage and Vz is the breakdown voltage. In the light of the above statements, choose the correct answer from the options given below (1) Both A and R are true and R is correct (2) Both A and R are true but R is NOT the correct explanation A explanation A (3) A is false but R is true (4) A is true but R is false

Q29.The logic operations performed by the given digital circuit is equivalent to: (1) NOR (2) AND (3) OR (4) NAND

Q29.A thin cylindrical rod of length 10 cm is placed horizontally on the principle axis of a concave mirror of focal length 20 cm. The rod is placed in a such a way that mid point of the rod is at 40 cm from the pole of mirror. The length of the image formed by the mirror will be 𝑥 cm. The value of 𝑥 is ______. 3

Q29.Unpolarised light of intensity 32 W m−2 passes through the combination of three polaroids such that the pass axis of the last polaroids is perpendicular to that of the pass axis of first polaroids. If intensity of emerging light is 3 W m−2, then the angle between pass axis of first two polaroids is _________°.

Q30.In a metre bridge experiment the balance point is obtained if the gaps are closed by 2 Ω and 3 Ω. A shunt of X Ω is added to 3 Ω resistor to shift the balancing point by 22. 5 cm. The value of X is ______.

Q30.Assume that protons and neutrons have equal masses. Mass of a nucleon is 1 . 6 × 10-27 kg and radius of 1 nucleus is 1 . 5 × 10-15 A 3 m. The approximate ratio of the nuclear density and water density is n × 1013. The value of n is _____.

Q30.A TV transmitting antenna is 98 m high and the receiving antenna is at the ground level. If the radius of the earth is 6400 km, the surface area covered by the transmitting antenna is approximately: JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper (1) 1240 km2 (2) 3942 km2 (3) 4868 km2 (4) 1549 km2 Q31. 0. 5 g of an organic compound (X) with 60% carbon will produce ×10−1 g of CO2 on complete combustion.

Q30.If 917 Å be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be Å.

Q30.The power radiated from a linear antenna of length l is proportional to (Given, λ = Wavelength of wave): (1) λ l (2) ( λl ) 2 (3) l (4) l2 λ2 λ

Q30.Statement I : When a Si sample is doped with Boron, it becomes P type and when doped by Arsenic it becomes N-type semi conductor such that P-type has excess holes and N-type has excess electrons. Statement II : When such P-type and N-type semi-conductors, are fused to make a junction, a current will automatically flow which can be detected with an externally connected ammeter. In the light of above statements, choose the most appropriate answer from the options given below. (1) Both Statement I and statement II are incorrect (2) Statement I is incorrect but statement II is correct (3) Both Statement I and statement II are correct (4) Statement I is correct but statement II is incorrect

Q30.When two resistance R1 and R2 connected in series and introduced into the left gap of a meter bridge and a resistance of 10 Ω is introduced into the right gap, a null point is found at 60 cm from left side. When R1 and R2 are connected in parallel and introduced into the left gap, a resistance of 3 Ω is introduced into the right- gap to get null point at 40 cm from left end. The product of R1 R2 is ______ Ω2

Q30.The amplitude of 15 sin(1000 πt) is modulated by 10 sin(4 πt) signal. The amplitude modulated signal contains frequencies of A. 500 Hz B. 2 Hz C. 250 Hz D. 498 Hz E. 502 Hz Choose the correct answer from the options given below JEE Main 2023 (12 Apr Shift 1) JEE Main Previous Year Paper (1) A and B only (2) A and C only (3) A and D only (4) A, D and E only

Q30.As per given figure A, B and C are the first, second and third excited energy levels of hydrogen atom n will be e. λ2 respectively. If the ratio of the two wavelengths (i. λ1 ) is 4n7 , then the value of

Q30.A light of energy 12 . 75 eV is incident on a hydrogen atom in its ground state. The atom absorbs the radiation and reaches to one of its excited states. The angular momentum of the atom in the excited state is 𝑥 – 15 – 𝜋× 10-17 eVs. The value of 𝑥 is ______ (use ℎ= 4 . 14 × 10 eVs, 𝑐= 3 × 108 m s 1)

Q30.In a screw gauge, there are 100 divisions on the circular scale and the main scale moves by 0 . 5 mm on a complete rotation of the circular scale. The zero of circular scale lies 6 divisions below the line of graduation when two studs are brought in contact with each other. When a wire is placed between the studs, 4 linear scale divisions are clearly visible while 46th division the circular scale coincide with the reference line. The diameter of the wire is ______ × 10-2 mm .

Q30.A monochromatic light is incident on a hydrogen sample in ground state. Hydrogen atoms absorb a fraction of light and subsequently emit radiation of six different wavelengths. The frequency of incident light is 𝑥× 1015 Hz. The value of x is ________ (Given ℎ= 4 . 25 × 10-15 eVs) Q31.25 mL of silver nitrate solution ( 1M ) is added dropwise to 25 mL of potassium iodide ( 1 . 05 M ) solution. The ion(s) present in very small quantity in the solution is/are (1) I- only (2) K+only (3) NO3- only (4) Ag+ and I-both

Q30.For hydrogen atom, 𝜆1 and 𝜆2 are the wavelengths corresponding to the transitions 1 and 2 respectively as 𝑥 shown in figure. The ratio of 𝜆1 and 𝜆2 is 32. The value of 𝑥 is ______.

Q30.Given below are two statements Statement I : For transmitting a signal, size of antenna (l) should be comparable to wavelength of signal (at least l = λ4 in dimension). Statement II : In amplitude modulation, amplitude of carrier wave remains constant (unchanged). In the light of the above statements, choose the most appropriate answer from the options given below JEE Main 2023 (31 Jan Shift 2) JEE Main Previous Year Paper (1) Both Statement I and Statement II are correct (2) Both Statement I and Statement II are incorrect (3) Statement I is incorrect but Statement II is (4) Statement I is correct but Statement II is correct incorrect

Q30.The decay constant for a radioactive nuclide is 1 . 5 × 10-5 s-1. Atomic weight of the substance is 60 g mole-1, 𝑁𝐴= 6 × 1023. The activity of 1 . 0 µ g of the substance is ________ × 1010 Bq.

Q1. Velocity (v) and acceleration (a) in two systems of units 1 and 2 are related as v2 = m2n v1 and a2 = mna1 respectively. Here m and n are constants. The relations for distance and time in two systems respectively are n2 n3 (1) = m T 2 m3 L1 = L2 and n2m T 1 = T2 (2) L1 = m2n4 L2 and T1 (3) L1 = n2m L2 and T1 = m2n4 T2 (4) n2m L1 = L2 and m2n4 T 1 = T2

Q1. Consider the efficiency of Carnot's engine is given by η = sinαβθ loge kTβx , where α and β are constants. If T is temperature, k is Boltzman constant, θ is angular displacement and x has the dimensions of length. Then, choose the incorrect option. (1) Dimensions of β is same as that of force. (2) Dimensions of α−1x is same as that of energy. (3) Dimensions of η−1 sin θ is same as that of αβ (4) Dimensions of α is same as that of β

Q1. Assertion A: Product of Pressure (P) and time (t) has the same dimension as that of coefficient of viscosity. Reason: Coefficient of viscosity = VelocityForcegradient (1) Both A and R true, and R is correct explanation of (2) Both A and R are true but R is NOT the correct A. explanation of A. (3) A is true but R is false. (4) A is false but R is true.

Q1. Given below are two statements: One is labelled as Assertion (A) and other is labelled as Reason (R) Assertion (A) : Time period of oscillation of a liquid drop depends on surface tension (S), if density of the liquid is ρ and radius of the drop is r, then T = 3 is dimensionally correct, where K is dimensionless. K√ρr3S 2 Reason (R) : Using dimensional analysis we get R.H.S. having different dimension than that of time period. In the light of above statements, choose the correct answer from the options given below. (1) Both (A) and (R) are true and (R) is the correct explanation of (A) (2) Both (A) and (R) are true but (R) is not the correct explanation of (A) (3) (A) is true but (R) is false (4) (A) is false but (R) is true

Q1. Two vectors A and B have equal magnitudes. If magnitude of A + B is equal to two times the magnitude of → → → → A − B, then the angle between A and B will be (1) cos−1( 35 ) (2) cos−1( 13 ) (3) sin−1( 13 ) (4) sin−1( 35 ) a + −b] = RT; P is pressure, V is volume, R is universal gas constant and 2 V