Tag Archives: JEE

Questions and Answers on Dimensional Analysis

Posted on April 2, 2020 by Timepersonified

Q1: Define the term ‘Dimension’   Answer: The term ‘dimension’ is used to refer to the physical nature of a quantity and the type of unit used to specify it. Mathematically dimensions of a physical quantity are the powers to which … Continue reading →

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Posted on March 23, 2015 by Timepersonified

When p-n junction diode is forward biased (A)depletion region is reduced and barrier height is increased (B) both depletion region and barrier height reduced (C) depletion region is widened and barrier height is reduced. (D) both depletion region and barrier … Continue reading →

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Posted on March 23, 2015 by Timepersonified

When npn transistor is used as amplifier (A) electrons move from base to collector (B) holes move from emitter to base (C) electrons move from collector to base (D) holes move from base to emitter.

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Posted on March 23, 2015 by Timepersonified

An α-particle of energy 5 MeV is scattered through 180° by a fixed uranium nucleus. The distance of the closest approach is of the order of (A) 1 Å (B) 10−10 cm  (C) 10−12 cm (D) 10−15 cm

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Posted on March 23, 2015 by Timepersonified

The binding energy per nucleon of deuteron and helium nucleus is 1.1 MeV and 7 MeV respectively. If two deuteron nuclei react to form a single helium nucleus, then the energy released is (A) 13.9 MeV (B) 26.9 MeV  (C) … Continue reading →

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Posted on March 23, 2015 by Timepersonified

A nucleus disintegrates into two nuclear parts which have their velocities in the ratio 2 : 1. The ratio of their nuclear sizes will be (A) 21/3 : 1 (B) 1 : 3 1/2  (C) 31/2 : 1 (D) 1 … Continue reading →

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Posted on March 23, 2015 by Timepersonified

A charged oil drop is suspended in a uniform field of 3 × 104 V/m so that it neither falls nor rises. The charge on the drop will be (take the mass of the charge = 9.9 × 10−15 kg … Continue reading →

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Posted on March 23, 2015 by Timepersonified

The work function of a substance is 4.0 eV. Then longest wavelength of light that can cause photoelectron emission from this substance approximately (A) 540 nm (B) 400 nm  (C) 310 nm (D) 220 nm

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Posted on March 23, 2015 by Timepersonified

According to Einstein’s photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal Vs the frequency, of the incident radiation gives straight line whose slope (A) depends on the nature of the metal used … Continue reading →

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Posted on March 23, 2015 by Timepersonified

A metal conductor of 1m rotates vertically about one of its ends at ω= 5rad/second. If the horizontal component of earth’s magnetic field is 0.3 × 10−4 T, then the e.m.f. developed between the two ends of the conductor is … Continue reading →

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