The total number of three-digit numbers, divisible by 3, which can be formed using the digits 1,3,5,8, if repetition of digits is allowed, is
Let the determinant of a square matrix A of order \( m \) be \( m - n \), where \( m \) and \( n \) satisfy \( 4m + n = 22 \) and \( 17m + 4n = 93 \). If \( \text{det} (n \, \text{adj}(\text{adj}(mA))) = 3^a 5^b 6^c \), then \( a + b + c \) is equal to:
A coil is placed in magnetic field such that plane of coil is perpendicular to the direction of magnetic field. The magnetic flux through a coil can be changed : A. By changing the magnitude of the magnetic field within the coil B. By changing the area of coil within the magnetic field C. By changing the angle between the direction of magnetic field and the plane of the coil D. By reversing the magnetic field direction abruptly without changing its magnitude. Choose the most appropriate answer from the options given below :
In an amplitude modulation, a modulating signal having amplitude of \(X V\) is superimposed with a carrier signal of amplitude \(Y V\) in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude \(2 YV\). The ratio of modulation index in the two cases respectively will be :
As shown in the figure, a long straight conductor with semi-circular are of radius \(\frac{\pi}{10} m\) is carrying current \(I =3 A\). The magnitude of the magnetic field at the center \(O\) of the arc is :(The permeability of the vacuum \(=4 \pi \times 10^{-7} NA ^{-2}\) )
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 \(600 \Omega\), the voltmeter with resistance \(1000 \Omega\) will be preferred over voltmeter with resistance \(4000 \Omega\).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
The starting material for convenient preparation of deuterated hydrogen peroxide \(\left(D_2 O _2\right)\) in laboratory is :
The effect of addition of helium gas to the following reaction in equilibrium state, is : \(PCl _5( g ) \rightleftharpoons PCl _3( g )+ Cl _2( g )\)
The correct order of bond enthalpy \(\left( kJ mol ^{-1}\right)\) is :
The speed of a swimmer is $4 km h ^{-1}$ in still water If the swimmer makes his strokes normal to the flow of river of width $1 km$, he reaches a point $750 m$ down the stream on the opposite bank.The speed of the river water is ___ $km h ^{-1}$