JEE 2020: Weekly Quiz -2 (16.06.2019) for JEE & BITSAT Exams

Question 1

The dimensional formula of modulus of elasticity is

Question 2

Which of the following is the smallest unit ?

Question 3

The percentage errors in quantities P, Q, R and S are 0.5%, 1%, 3% and 1.5% respectively in the measurement of a physical quantity

The maximum percentage error in the value of A will be :

Question 4

The density of a material in the shape of a cube is determined by measuring three sides of the cube and its mass. If the relative errors in measuring the mass and length are respectively 1.5% and 1%, the maximum error in determining the density is :

Question 5

In the following ‘I’ refers to current and other symbols have their usual meaning. Choose the option that corresponds to the dimensions of electrical conductivity:

Question 6

The magnitude of the average electric field normally present in the atmosphere just above the surface of the Earth is about 150 N/C, directed inward towards the center of the Earth. This gives the total net surface charge carried by the Earth to be :
[Given

]

Question 7

A spherically symmetric charge distribution is characterised by a charge density having the following variation:

Where r is the distance from the centre of the charge distribution and

is a constant. The electric field at an internal point (r < R) is:

Question 8

The potential (in volts) of a charge distribution is given by

V(z) does not depend on x and y. If this potential is generated by a constant charge per unit volume ρ₀ (in units of

) which is spread over a certain region, then choose the correct statement?

Question 9

Shown in the figure are two point charges +Q and -Q inside the cavity of a spherical shell. The charges are kept near the surface of the cavity on opposite sides of the centre of the shell. If

is the surface charge density on the inner surface and

net charge on it and

the surface charge density on the outer surface and

net charge on it then:

Question 10

A thin disc of radius b = 2a has a concentric hole of radius ’a’ in it (see figure). It carries uniform surface charge

on it. If the electric field on its axis at height ’h’ (h<<a) from its centre is given as ’Ch’ then value of ‘C’ is:

Question 11

The amount of arsenic pentasulphide that can be obtained when 35.5 g arsenic acid is treated with excess H₂S in the presence of conc. HCl (assuming100% conversion) is:

Question 12

An unknown chlorohydrocarbon has 3.55% of chlorine. If each molecule of the hydrocarbon has one chlorine atom only; chlorine atoms present in 1 g of chlorohydrocarbon are :
(Atomic wt. of Cl=35.5 u; Avogadro constant

Question 13

6.02×10²⁰ molecules of urea are present in 100 ml of its solution. The concentration of urea solution is

Question 14

The molecular formula of a commercial resin used for exchanging ions in water softening is C₈H₇SO₃Na (Mol. wt. 206). What would be the maximum uptake of Ca²⁺ ions by the resin when expressed in mole per gram resin?

Question 15

The ratio of mass percent of C and H of an organic compound C_XH_YO_Z

is 6 : 1. If one molecule of the above compound

contains half as much oxygen as required to burn one molecule of compound

completely to

and

The empirical formula of compound

is :

Question 16

Which of the following statements is false?

Question 17

Energy of H-atom in the ground state is -13.6 eV, hence energy in the second excited state is:

Question 18

The energy of an electron in first Bohr orbit of H-atom is -13.6eV. The energy value of electron in the excited state of Li²⁺ is :

Question 19

Consider the following nuclear reactions

The number of neutrons in the element L is

Question 20

In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. certainity with which the position of the electron can be located is (h = 6.6 × 10^–34 kg m²s^–1, mass of electron e_m = 9.1 × 10^–31kg)