Practice Questions

Q17.In the given circuit. C1 = 2μF, C2 = 0. 2μF, C3 = 2μF, C4 = 4μF, C5 = 2μF, C6 = 2μF. The charge stored on capacitor C4 is ______ μC. JEE Main 2023 (11 Apr Shift 2) JEE Main Previous Year Paper

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.A small object at rest, absorbs a light pulse of power 20 mW and duration 300 ns. Assuming speed of light as 3 × 108 m s-1. The momentum of the object becomes equal to : (1) 0 . 5 × 10-17 kg m s-1 (2) 2 × 10-17 kg m s-1 (3) 3 × 10-17 kg m s-1 (4) 1 × 10-17 kg m s-1

Q17.If a source of electromagnetic radiation having power 15 kW produces 1016 photons per second, the radiation belongs to a part of spectrum is : (Take Planck constant ℎ = 6 × 10-34 J s) (1) Micro waves (2) Ultraviolet rays (3) Gamma rays (4) Radio waves

Q17.A metallic surface is illuminated with radiation of wavelength 𝜆, the stopping potential is 𝑉0. If the same 𝑉0 surface is illuminated with radiation of wavelength 2𝜆, the stopping potential becomes . The threshold 4 wavelength for this metallic surface will be (1) 3𝜆 (2) 4𝜆 (3) 3 (4) 𝜆 2𝜆 4

Q17.A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of 𝜆. An alpha particle having certain kinetic energy has the same de-Brogle wavelength 𝜆. The ratio of kinetic energy of proton and that of alpha particle is : (1) 2 : 1 (2) 4 : 1 (3) 1 : 2 (4) 1 : 4 JEE Main 2023 (01 Feb Shift 1) JEE Main Previous Year Paper

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.The half life of a radioactive substance is 𝑇. The time taken, for disintegrating 7 𝑡ℎ part of its original mass will 8 be: (1) 2𝑇 (2) 3𝑇 (3) 𝑇 (4) 8𝑇

Q17.A cell of emf 90 V is connected across series combination of two resistors each of 100 Ω resistance. A voltmeter of resistance 400 Ω is used to measure the potential difference across each resistor. The reading of the voltmeter will be: (1) 40 V (2) 45 V (3) 80 V (4) 90 V

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.Ratio of thermal energy released in two resistor R and 3R connected in parallel in an electric circuit is : (1) 3 : 1 (2) 1 : 1 (3) 1 : 3 (4) 1 : 27

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.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

Q18.The de Broglie wavelength of an electron having kinetic energy E is λ . If the kinetic energy of electron becomes E , then its de-Broglie wavelength will be: 4 (1) √2λ (2) λ √2 (3) λ (4) 2λ 2

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.The angular momentum for the electron in Bohr’s orbit is 𝐿. If the electron is assumed to revolve in second orbit of hydrogen atom, then the change in angular momentum will be (1) Zero (2) 2𝐿 (3) 𝐿 (4) 𝐿 2

Q18.The number density of free electrons in copper is nearly 8 × 1028 m−3 . A copper wire has its area of cross- section = 2 × 10−6 m2 and is carrying a current of 3. 2 A . The drift speed of the electrons is _____ ×10−6 m s−1 .

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.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 .

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

Q18.In this figure the resistance of the coil of galvanometer G is 2 Ω. The emf of the cell is 4 V. The ratio of potential difference across C1 and C2 is (1) 1 (2) 45 (3) 5 (4) 3 4 4

Q18.A student is provided with a variable voltage source V , a test resistor RT = 10Ω , two identical galvanometers G1 and G2 and two additional resistors, R1 = 10MΩ and R2 = 0. 001Ω . For conducting an experiment to verify ohm's law, the most suitable circuit is: (1) (2) (3) (4) JEE Main 2023 (06 Apr Shift 2) JEE Main Previous Year Paper

Q18.If each diode has a forward bias resistance of 25Ω in the below circuit, Which of the following options is correct? (1) I1 = 1 (2) I2 = 1 I2 I3 I1 I3 (3) = 2 (4) = 1 I2 I4

Q18.The H amount of thermal energy is developed by a resistor in 10 s when a current of 4 A is passed through it. If the current is increased to 16 A , the thermal energy developed by the resistor in 10 s will be (1) H (2) 16H (3) H (4) 4H 4