Practice Questions

Q28.A light ray is incident, at an incident angle θ1 , on the system of two plane mirrors M1 and M2 having an inclination angle 75° between them (as shown in figure). After reflecting from mirror M1 it gets reflected back by the mirror M2 with an angle of reflection 30° . The total deviation of the ray will be _____ degree.

Q28.The graph between 1 and 1 for a thin convex lens in order to determine its focal length is plotted as shown in u v the figure. The refractive index of lens is 1. 5 and its both the surfaces have same radius of curvatures R. The value of R will be _____ cm. (Where u = object distance, v = image distance)

Q28.A singly ionized magnesium atom (A = 24) ion is accelerated to kinetic energy 5 keV, and is projected perpendicularly into a magnetic field B of the magnitude 0. 5 T. The radius of path formed will be _____ cm.

Q28.A wire of length 314 cm carrying current of 14 A is bent to form a circle. The magnetic moment of the coil is A −m2 . [Given π = 3. 14]

Q28.A resistor develops 300 J of thermal energy in 15 s, when a current of 2 A is passed through it. If the current increases to 3 A, the energy developed in 10 s is _____ J.

Q29.The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630Å is 0. 42 V . If the threshold frequency is x × 1013 s, where x is (nearest integer): (Given, speed light = 3 × 108 m s−1 . Planck's constant = 6. 63 × 10−34 J s)

Q29.As per the given circuit, the value of current through the battery will be _____ A. JEE Main 2022 (26 Jun Shift 1) JEE Main Previous Year Paper

Q29.A potential barrier of 0. 4 V exists across a p-n junction. An electron enters the junction from the n -side with a speed of 6. 0 × 105 m s−1 . The speed with which electron enters the p side will be x3 × 105 m s−1 , then the value of x is _____.: (Given mass of electron = 9 × 10−31 kg, charge on electron = 1. 6 × 10−19 C.)

Q29.A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If rd and rp are the radii of their circular paths respectively, then the ratio rd will be √x : 1 where rp x is _____ .

Q29.In a series LCR circuit, the inductance, capacitance and resistance are 𝐿= 100 mH, C = 100 𝜇Fand 𝑅= 10 Ω respectively. They are connected to an AC source of voltage 220 V and frequency of 50 Hz. The approximate value of current in the circuit will be _____ 𝐴.

Q29. x is the ratio of energies of photons produced due to transition of an electron of hydrogen atom from its x+4 (i) third permitted energy level to the second level and (ii) the highest permitted energy level to the second permitted level. The value of x will be

Q29.In the given circuit, the value of current IL will be _____ mA. (When RL = 1 kΩ)

Q29.An object ' O' is placed at a distance of 100 cm in front of a concave mirror of radius of curvature 200 cm as shown in the figure. The object starts moving towards the mirror at a speed 2 cm s−1 . The position of the image from the mirror after 10 s will be at _____ cm.

Q29.A conducting circular loop is placed in X −Y plane in presence of magnetic field B = (3t3ˆj 3t2ˆk) in SI unit. If the radius of the loop is 1 m, the induced emf in the loop, at time, t = 2 s is nπ V. The value of n is _____ .

Q29.In a hydrogen spectrum λ be the wavelength of first transition line of Lyman series. The wavelength difference will be " aλ" between the wavelength of 3rd transition line of Paschen series and that of 2nd transition line of Balmer Series where a = _____.

Q29.The total current supplied to the circuit as shown in figure by the 5 V battery is _____ A.

Q29.A beam of monochromatic light is used to excite the electron in Li++ from the first orbit to the third orbit. The wavelength of monochromatic light is found to be x × 10−10 m. The value of x is _____ . [Given hc = 1242 eV nm]

Q29.Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the two beams are π and π at points A and B respectively. The difference between the 2 3 resultant intensities at the two points is xI . The value of x will be _____ .

Q29.When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1 . When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v2 . If v2 = xv1 , the value of x will be _____ .

Q29.Two lighter nuclei combine to form a comparatively heavier nucleus by the relation given below: 2𝑋+1 2𝑋=1 4𝑌2 The binding energies per nucleon 2𝑋1 and 4𝑌2 are 1 . 1MeV and 7 . 6MeV respectively. The energy released in this process is_____ MeV.

Q29.A Zener of breakdown voltage VZ = 8 V and maximum Zener current, IZM = 10 mA is subjected to an input voltage Vi = 10 V with series resistance R = 100 Ω . In the given circuit RL represents the variable load resistance. The ratio of maximum and minimum value of RL is _____ .

Q29.A 8V Zener diode along with a series resistance 𝑅 is connected across a 20 V supply (as shown in the figure). If the maximum Zener current is 25 mA, then the minimum value of 𝑅 will be _____ Ω.

Q29.In a Young's double slit experiment, a laser light of 560 nm produces an interference pattern with consecutive bright fringes' separation of 7 . 2 mm. Now another light is used to produce an interference pattern with consecutive bright fringes' separation of 8 . 1 mm. The wavelength of second light is _____ nm .

Q29.The X −Y plane be taken as the boundary between two transparent media M1 and M2 . M1 in Z ≥0 has a refractive index of √2 and M2 with Z < 0 has a refractive index of √3. A ray of light travelling in M1 along → the direction given by the vector A = 4√3i −3√3j −5ˆk, is incident on the plane of separation. The value of difference between the angle of incident in M1 and the angle of refraction in M2 will be _____ degree.

Q29.An AC source is connected to an inductance of 100 mH , a capacitance of 100 μF and a resistance of 120 Ω as shown in figure. The time in which the resistance having a thermal capacity 2 J ∘C−1 will get heated by 16°C is _____ s.