Practice Questions

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

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

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.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 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]

Q30.A transistor is used in an amplifier circuit in common emitter mode. If the base current changes by 100 μA , it brings a change of 10 mA in collector current. If the load resistance is 2 kΩ and input resistance is 1 kΩ, the value of power gain is x × 104 . The value of x is _____ .

Q30.The one division of main scale of vernier callipers reads 1 mm and 10 divisions of Vernier scale is equal to the 9 divisions on main scale. When the two jaws of the instrument touch each other the zero of the Vernier lies to the right of zero of the main scale and its fourth division coincides with a main scale division. When a spherical bob is tightly placed between the two jaws, the zero of the Vernier scale lies in between 4. 1 cm and 4. 2 cm and 6th Vernier division coincides with a main scale division. The diameter of the bob will be _____ 10−2 cm. Q31. 250 g solution of D -glucose in water contains 10. 8% of carbon by weight. The molality of the solution is nearest to (Given: Atomic Weights are H = 1u; C = 12 u; O = 16 u ) (1) 1. 03 (2) 2. 06 (3) 3. 09 (4) 5. 40 JEE Main 2022 (27 Jul Shift 1) JEE Main Previous Year Paper

Q30.A thin prism of angle 6° and refractive index for yellow light (nY)1. 5 is combined with another prism of angle 5° and nY = 1. 55 . The combination produces no dispersion. The net average deviation (δ) produced by the combination is ( x1 ) ° . The value of x is _____ .

Q30.A travelling microscope is used to determine the refractive index of a glass slab. If 40 divisions are there in 1 cm on main scale and 50 Vernier scale divisions are equal to 49 main scale divisions, then least count of the travelling microscope is _____ ×10−6 m.

Q30.The height of a transmitting antenna at the top of a tower is 25 m and that of receiving antenna is, 49 m. The maximum distance between them, for satisfactory communication in LOS (Line-Of-Sight) is K√5 × 102 m. The value of K is _____ . (Assume radius of Earth is 64 × 105 m) [Calculate upto nearest integer value]

Q30.A transistor is used in common-emitter mode in an amplifier circuit. When a signal of 10 mV is added to the base-emitter voltage, the base current changes by 10μA and the collector current changes by 1. 5 mA . The load resistance is 5kΩ . The voltage gain of the transistor will be _____ .

Q30.The typical transfer characteristic of a transistor in CE configuration is shown in figure. A load resistor of 2 kΩ is connected in the collector branch of the circuit used. The input resistance of the transistor is 0 . 50 kΩ. The voltage gain of the transistor is

Q30.An antenna is placed in a dielectric medium of dielectric constant 6. 25. If the maximum size of that antenna is 5. 0 mm, it can radiate a signal of minimum frequency of _____ GHz. (Given μr = 1 for dielectric medium) Q31. 120 g of an organic compound which contains only carbon and hydrogen on complete combustion gives 330 g of CO2 and 270 g of water. The percentage of carbon and hydrogen in the organic compound are respectively (1) 25 and 75 (2) 40 and 60 (3) 60 and 40 (4) 75 and 25

Q30.A telegraph line of length 100 km has a capacity of 0. 01 μF km−1 and it carries an alternating current at 0. 5 kilo cycle per second. If minimum impedance is required, then the value of the inductance that needs to be introduced in series is _____ mH . (If π = √10 )

Q30.The Vernier constant of Vernier callipers is 0. 1 mm and it has zero error of (−0. 05 cm). While measuring diameter of a sphere, the main scale reading is 1. 7 cm and coinciding vernier division is 5 . The corrected diameter will be _____ ×10−2 cm.

Q30.Two ideal diodes are connected in the network as shown in figure. The equivalent resistance between A and B is _____ Ω.

Q30.In an experiment with a convex lens. The plot of the image distance (v′) against the object distance (μ′) measured from the focus gives a curve v′μ′ = 225 . If all the distances are measured in cm. The magnitude of the focal length of the lens is _____ cm.

Q30.In a vernier callipers, each cm on the main scale is divided into 20 equal parts. If tenth vernier scale division coincides with nineth main scale division. Then the value of vernier constant will be _____ ×10−2 mm

Q30.A freshly prepared radioactive source of half life 2 hours 30 minutes emits radiation which is 64 times the permissible safe level. The minimum time, after which it would be possible to work safely with source, will be _____ hours.

Q30.In the circuit shown below, maximum Zener diode current will be _____ mA .