Practice Questions

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

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 required height of a TV tower which can cover the population of 6 . 03 lakh is ℎ. If the average population density is 100 per square km and the radius of earth is 6400 km, then the value of ℎ will be _____ m.

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

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.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.The cut-off voltage of the diodes (shown in figure) in forward bias is 0. 6 V. The current through the resister of 40Ω is _____ mA .

Q30.In an experiment of 𝐶𝐸 configuration of 𝑛- 𝑝- 𝑛 transistor, the transfer characteristics are observed as given in figure. JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper If the input resistance is 200Ω and output resistance is 60Ω, the voltage gain in this experiment will be _____ .

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.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 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.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 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 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.A student in the laboratory measures thickness of a wire using screw gauge. The readings are 1. 22 mm, 1. 23 mm, 1. 19 mm and 1. 20 mm . The percentage error is 121x % . The value of x is _____ .

Q31.The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is: [Given: The threshold frequency of platinum is 1 . 3 × 1015 s-1 and h = 6 . 6 × 10-34Js] (1) 8 . 58 × 10-19J (2) 9 . 76 × 10-20J (3) 3 . 21 × 10-14J (4) 6 . 24 × 10-16J

Q37.Amongst baking soda, caustic soda and washing soda carbonate anion is present in : (1) Washing Soda only (2) washing soda and caustic soda only. (3) washing soda and baking soda only. (4) baking soda, caustic soda and washing soda.

Q51.Chlorophyll extracted from the crushed green leaves was dissolved in water to make 2 L solution of Mg of concentration 48ppm. The number of atoms of Mg in this solution is x × 1020 atoms. The value of x is (Nearest Integer) (Given : Atomic mass of Mg is 24 g mol−1 , NA = 6. 02 × 1023 mol−1 )

Q51.A box contains 0. 90 g of liquid water in equilibrium with water vapour at 27°C. The equilibrium vapour pressure of water at 27°C 32. 0 Torr. When the volume of the box is increased, some of the liquid water evaporates to maintain the equilibrium pressure. If all the liquid water evaporates, then the volume of the box must be ______ litre. [nearest integer] (Given: R = 0. 082 L atm K−1 mol−1 _ (Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.) Q52. 2. 2 g of nitrous oxide (N2O) gas is cooled at a constant pressure of 1 atm from 310 K to 270 K causing the compression of the gas from 217. 1 mL to 167. 75 mL. The change in internal energy of the process, △U is ′−x′J. The value of ′x′ is _____. [nearest integer] (Given: atomic mass of N = 14 g mol−1 and of O = 16 g mol−1 . Molar heat capacity of N2O is 100 JK−1 mol−1 )

Q51.If the uncertainty in velocity and position of a minute particle in space are, 2. 4 × 10−26(ms−1) and 10−7(m) respectively. The mass of the particle in g is___(Nearest integer) (Given : h = 6. 626 × 10−34 Js) Q52. 2 NOCl(g) ⇌2 NO(g) + Cl2(g) In an experiment, 2. 0 moles of NOCl was placed in a one-litre flask and the concentration of NO after equilibrium established, was found to be 0. 4 mol /L. The equilibrium constant at 30 °C is_____ ×10−4 .

Q51.Consider an imaginary ion 48X322 - . The nucleus contains 'a' % more neutrons than the number of electrons in the ion. The value of 'a' is

Q51.A protein 'A' contains 0 . 30% of glycine (molecular weight 75). The minimum molar mass of the protein 'A' is____ × 103 g mol-1 [nearest integer] JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper