Practice Questions

Q16.A parallel plate capacitor has plate area 40 cm2 and plates separation 2 mm . The space between the plates is filled with a dielectric medium of a thickness 1 mm and dielectric constant 5 . The capacitance of the system is: (1) 24ε0 F (2) 103 ε0 F (3) 10 3 ε0 F (4) 10ε0 F

Q16.The variation of stopping potential V0 as a function of the frequency ( 𝜈) of the incident light for a metal is shown in figure. The work function of the surface is JEE Main 2023 (10 Apr Shift 2) JEE Main Previous Year Paper (1) 2 . 98 eV (2) 2 . 07 eV (3) 1 . 36 eV (4) 18 . 6 eV

Q16.The critical angle for a denser-rarer interface is 45°. The speed of light in rarer medium is 3 × 108 m s-1. The speed of light in the denser medium is: (1) 3 . 12 × 107 m s-1 (2) 5 × 107 m s-1 (3) 2 . 12 × 108 m s-1 (4) √2 × 108 m s-1

Q16.A parallel plate capacitor with air between the plate has a capacitance of 15 pF . The separation between the plate becomes twice and the space between them is filled with a medium of dielectric constant 3. 5 . Then the capacitance becomes x 4 pF . The value of x is____. JEE Main 2023 (24 Jan Shift 2) JEE Main Previous Year Paper

Q17.The equivalent resistance between A and B as shown in figure is: (1) 10 kΩ (2) 5 kΩ (3) 20 kΩ (4) 30 kΩ

Q17.A point charge of 10 µC is placed at the origin. At what location on the X -axis should a point charge of 40 µC be placed so that the net electric field is zero at x = 2 cm on the X -axis ? (1) x = 6 cm (2) x = 4 cm (3) x = 8 cm (4) x = –4 cm

Q17.Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : For measuring the potential difference across a resistance of 600 Ω, the voltmeter with resistance 1000 Ω will be preferred over voltmeter with resistance 4000 Ω . Reason R : Voltmeter with higher resistance will draw smaller current than voltmeter with lower resistance. In the light of the above statements, choose the most appropriate answer from the options given below (1) A is not correct but R is correct (2) Both A and R are correct and R is the correct explanation of A (3) Both A and R are correct but R is not the correct (4) A is correct but R is not correct explanation of A JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper

Q17.A uniform metallic wire carries a current 2 A, when 3. 4 V battery is connected across it. The mass of uniform metallic wire is 8. 92 × 10−3 kg, density is 8. 92 × 103 kg m−3 and resistivity is 1. 7 × 10−8 Ω −m The length of wire is : (1) l = 6. 8 m (2) l = 10 m (3) l = 5 m (4) l = 100 m

Q17.An electric dipole of dipole moment is 6. 0 × 10−6 C m placed in a uniform electric field of 1. 5 × 103 N C−1 in such a way that dipole moment is along electric field. The work done in rotating dipole by 180° in this field will be_______ mJ.

Q17.Different combination of 3 resistors of equal resistance R are shown in the figures. The increasing order for power dissipation is: (A) (B) JEE Main 2023 (13 Apr Shift 1) JEE Main Previous Year Paper (C) (D) (1) PB < PC < PD < PA (2) PC < PD < PA < PB (3) PC < PB < PA < PD (4) PA < PB < PC < PD

Q17.The de Broglie wavelength of a molecule in a gas at room temperature 300 K is 𝜆1. If the temperature of the gas is increased to 600 K, then the de Broglie wavelength of the same gas molecule becomes JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper 1 (1) 2𝜆1 (2) √2𝜆1 (3) 1 (4) 2𝜆1 √2𝜆1

Q17.The equivalent resistance between A and B is _______. JEE Main 2023 (30 Jan Shift 2) JEE Main Previous Year Paper . (1) 2 Ω (2) 1 Ω 3 2 (3) 3 Ω (4) 1 Ω 2 3

Q17.As shown in the figure, two parallel plate capacitors having equal plate area of 200 cm2 are joined in such a way that a ≠b. The equivalent capacitance of the combination is xε0F . The value of x is _____.

Q17.In a Young’s double slit experiment, the ratio of amplitude of light coming from slits is 2 : 1. The ratio of the maximum to minimum intensity in the interference pattern is (1) 9 : 4 (2) 25 : 9 (3) 2 : 1 (4) 9 : 1

Q17.From the photoelectric effect experiment, following observations are made. Identify which of these are correct A. The stopping potential depends only on the work function of the metal. B. The saturation current increases as the intensity of incident light increases. C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light. D. Photoelectric effect can be explained using wave theory of light. Choose the correct answer from the options given below: (1) B, C only (2) A, C, D only (3) B only (4) A, B, D only

Q17.The number of turns of the coil of a moving coil galvanometer is increased in order to increase current sensitivity by 50%. The percentage change in voltage sensitivity of the galvanometer will be : (1) 100% (2) 50% (3) 75% (4) 0% JEE Main 2023 (31 Jan Shift 2) JEE Main Previous Year Paper

Q18.Consider the following radioactive decay process: 𝛼 𝛽- 𝛾 𝛼 𝛽+ 𝛾 218𝐴84 ⟶𝐴1 ⟶𝐴2 ⟶𝐴3 ⟶𝐴4 ⟶𝐴5 ⟶𝐴6 The mass number and the atomic number of A6 are given by: (1) 210 and 82 (2) 210 and 84 (3) 210 and 80 (4) 211 and 80

Q18.Two radioactive elements 𝐴 and 𝐵 initially have same number of atoms. The half life of 𝐴 is same as the average life of 𝐵. If 𝜆𝐴 and 𝜆𝐵 are decay constants of 𝐴 and 𝐵 respectively, then choose the correct relation from the given options. (1) 𝜆𝐴ln2 = 𝜆𝐵 (2) 𝜆𝐴= 𝜆𝐵 (3) 𝜆𝐴= 𝜆𝐵ln2 (4) 𝜆𝐴= 2𝜆𝐵

Q18.A free neutron decays into a proton but a free proton does not decay into neutron. This is because (1) neutron is an uncharged particle (2) proton is a charged particle (3) neutron is a composite particle made of a proton (4) neutron has larger rest mass than proton and an electron

Q18.A null point is found at 200 cm in potentiometer when cell in secondary circuit is shunted by 5 Ω . When a resistance of 15 Ω is used for shunting null point moves to 300 cm . The internal resistance of the cell is ______ Ω .

Q18.If a copper wire is stretched to increase its length by 20% . The percentage increase in resistance of the wire is _____%.

Q18. The current flowing through R2 is : (1) 3 2 A (2) 12 A (3) 1 3 A (4) 14 A

Q18.In the given circuit, the equivalent resistance between the terminal A and B is ____ Ω

Q18.A capacitor has capacitance 5 µF when its parallel plates are separated by air medium of thickness d. A slab of material of dielectric constant 1. 5 having area equal to that of plates but thickness d2 is inserted between the plates. Capacitance of the capacitor in the presence of slab will be ______ µF .

Q18.The current flowing through a conductor connected across a source is 2 A and 1. 2 A at 0oC and 100oC respectively. The current flowing through the conductor at 50oC will be _____ × 102 mA .