Ncert solutions for class 12 physics English medium updated 2021-22 .
NCERT Solutions for Class 12 Physics Chapter 15 Communication Systems. Question 1.At which of the following frequency/frequencies the communication will not be reliable for a receiver situated beyond the horizon:(a) 10 kHz(b) 10 MHz(c) 1 GHz(d) 1000 GHzAnswer:(b) is correct. Here (c) and (d) frequencies have high penetration power so the earth will absorb them. Radiation … Read more
NCERT Solutions for Class 12 Physics Chapter 14 Electronics Devices. Question 1.In an n-type silicon, which of the following statement is true :(a) Electrons are majority carriers and trivalent atoms are the dopants.(b) Electrons are minority carriers and pentavalent atoms are the dopants.(c) Holes are minority carriers and pentavalent atoms are the doplants.(d) Holes are … Read more
NCERT Solutions for Class 12 Physics Chapter 13 Nuclei. Question 1.(a) Two stable isotopes of lithium 63Li and 73Li have respective abundance of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u respectively. Find the atomic weight of lithium.(b) Boron has two stable isotopes 105Li and 115Li .Their respective masses are 10.01294 u and 11.00931 u and the atomic weight … Read more
NCERT Solutions for Class 12 Physics Chapter 12 Atoms. Question 1.Choose the correct alternative from clues given at end of each statement: The size of the atom in Thomson’s model is the atomic size in Rutherford’s model.(much greater than/no different from/much less than.) In the ground state of…………… electrons are in stable equilibrium, while in … Read more
NCERT Solutions for Class 12 Physics Chapter 11 Dual Nature of Radiation and Matter. Question 1.Find the(a) maximum frequency, and(b) minimum wavelength of X-rays produced by 30 kV electrons.Answer:Question 2.The work function of caesium metal is 2.14 eV. When light of frequency 6 x 1014 Hz is incident on the metal surface, photo emission of electrons … Read more
NCERT Solutions for Class 12 Physics Chapter 10 Wave Optics. Question 1.Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of(a) reflected, and(b) refracted light ? Refractive index of water is 1.33. (C.B.S.E. Sample Paper 1991)Answer:(a) For reflected light wavelength is unchanged i. e.X = … Read more
NCERT Solutions for Class 12 Physics Chapter 9 Ray Optics and Optical Instruments Question 1.A small candle 2.5 cm in size is placed 27 cm in front of a concave mirror of a radius of curvature of 36 cm. At what distance from the mirror should a screen be placed in order to receive a … Read more
NCERT Solutions for Class 12 Physics Chapter 8 Electromagnetic Waves. Question 1.Figure shows a capacitor made of two circular plates each of radius 12 cm and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in figure). The charging current is constant and equal to 0.15 A.(a) Calculate the … Read more
NCERT Solutions for Class 12 Physics Chapter 7 Alternating Current. Question 1.A 100 Ω resistor is connected to a 220 V, 50 Hz ac supply.(a) What is the rms value of current in the circuit?(b) What is the net power consumed over a full cycle?Answer: Question 2.(a) The peak voltage of an a.c. supply is … Read more
NCERT Solutions for Class 12 Physics Chapter 6 Electromagnetic Induction. Question 1.Predict the direction of induced current in the situations described by the following Fig. 2(a) to (f). Answer:(a) By Lenz’s law, the face of the coil towards the south pole of the magnet opposes the south pole. So this face should behave as the … Read more
