NEET 2021

184 Questions • 180 Minutes • 2021

Take This Paper Online

All Questions — Click to View Solution

Q61
The effective resistance of a parallel connection that consists of four wires of equal length, equal area of cross-section and same material is 0.25 Ω. What will be the effective resistance if they are connected in series?
View Answer & Solution
Q62
Column-I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations involving electrical quantities. Match Column- I and Column-II with appropriate relations. [table] Column-I | Column-II ; (A) Drift Velocity | (P) $\frac{m}{ne^2\rho}$ ; (B) Electrical Resistivity | (Q) $nev_d$ ; (C) Relaxation Period | (R) $\frac{eE}{m}\tau$ ; (D) Current Density | (S) $\frac{E}{J}$ [/table]
View Answer & Solution
Q63
Polar molecules are the molecules:
View Answer & Solution
Q64
A thick current carrying cable of radius 'R' carries current 'I' uniformly distributed across its cross-section. The variation of magnetic field B(r) due to the cable with the distance 'r' from the axis of the cable is represented by:
View Answer & Solution
Q65
A capacitor of capacitance 'C', is connected across an ac source of votlage V, given by $V = V_0 \sin \omega t$ The displacement current between the plates of the capacitor, would then be given by:
View Answer & Solution
Q66
For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?
View Answer & Solution
Q67
A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since:
View Answer & Solution
Q68
The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nm, when it delivers the power of $3.3 \times 10^{-3}$ watt will be: (h = $6.6 \times 10^{-34}$ Js)
View Answer & Solution
Q69
A convex lens 'A' of focal length 20 cm and a concave lens 'B' of focal length 5 cm are kept along the same axis with a distance 'd' between them. If a parallel beam of light falling on 'A' leaves 'B' as a parallel beam, then the distance 'd' in cm will be:
View Answer & Solution
Q70
An electromagnetic wave of wavelength '$\lambda$' is incident on a photosensitive surface of negligible work function. If 'm' mass is of photoelectron emitted from the surface has de-Broglie wavelength $\lambda_d$, then:
View Answer & Solution
Q71
A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding energy per nucleon of unfragmented nuclei is 7.6 MeV while that of fragments is 8.5 MeV. The total gain in the Binding Energy in the process is:
View Answer & Solution
Q72
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be:
View Answer & Solution
Q73
A radioactive nucleus $^A_ZX$ undergoes spontaneous decay in the sequence $^A_ZX \rightarrow\ _{Z-1}B \rightarrow\ _{Z-3}C \rightarrow\ _{Z-2}D$, where Z is the atomic number of element X. The possible decay particles in the sequence are:
View Answer & Solution
Q74
The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.
View Answer & Solution
Q75
Consider the following statements (A) and (B) and identify the correct answer. (A) A zener diode is Connected in reverse bias, when used as a voltage regulator. (B) The potential barrier of p-n junction lies between 0.1 V to 0.3 V.
View Answer & Solution
Q76
A particle moving in a circle of radius R with a uniform speed takes a time T to complete one revolution. If this particle were projected with the same speed at an angle '$\theta$' to the horizontal, the maximum height attained by it equals 4R. The angle of projection, $\theta$, is then given by:
View Answer & Solution
Q77
A car starts from rest and accelerates at 5 $m/s^2$. At t = 4 s, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at t = 6s ?
View Answer & Solution
Q78
A ball of mass 0.15 kg is dropped from a height 10 m, strikes the ground and rebounds to the same height. The magnitude of impulse imparted to the ball is (g = 10 $m/s^2$) nearly:
View Answer & Solution
Q79
From a circular ring of mass 'M' and radius 'R' an arc corresponding to a 90° sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the centre of the ring and perpendicular to the plane of the ring is 'K' times '$MR^2$'. Then the value of 'K' is:
View Answer & Solution
Q80
A particle of mass 'm' is projected with a velocity $v = kV_e$ (k < 1) from the surface of the earth. The maximum height above the surface reached by the particle is:
View Answer & Solution
Paper Info
  • Exam: NEET
  • Year: 2021
  • Questions: 184
  • Duration: 180 mins
Take Online All Papers