In a Carnot engine, efficiency is 40% at hot reservoir temperature T. For efficiency to be 50%, what shall be the temperature of the hot reservoir?
The figure below shows four cells E, F, G and H of emfs 2 V, 1 V, 3 V and 1 V and internal resistances 2Ω , 1Ω , 3Ω and 1Ω , respectively.
The potential difference between points B and D is
To get an output 1 from the circuit shown in the figure, the input must be
In the figure shown pulley is massless. Initially the blocks are held at a height such that spring is in its natural length. The amplitude and velocity amplitude of block B1 respectively are (there is no slipping anywhere)
Bullets of mass 0.03 kg each hit a plate at the rate of 200 bullets per second with a velocity of 50 ms-1 and reflect back with a velocity of 30 ms-1. The average force (in Newton) acting on the plate is
What is the minimum energy required to launch a satellite of mass ‘m' from the surface of the earth of mass ‘M’ and radius ‘R’ at an altitude 2R?
The standard reduction potential at 298 K for the following half cell reaction are given below
Zn2+ + 2e- → Zn E0 = − 0.762 V
Cr+3 + 3 e- → Cr E0 = − 0.740 V
2 H+ + 2 e- → H2 E0 = − 0.0 V
Fe+3 + e- → Fe+2 E0 = − 0.770 V
Which one is the strongest reducing agent?
Which one of the following informations can be obtained on the basis of Le Chatelier principle ?
Consider the following compounds :
I. HCHO II.CH₃CHO III. CH₃COCH₃
The reactivities of these compounds are such that
Among the properties (a) reducing (b) oxidising (c) complexing, the set of properties shown by CN⁻ ion towards metal species is
If α, β and γ are the roots of the equation x3 + px2 + q = 0, where q ≠ 0 and Δ = , then Δ equals
If λ is the least value of |Z−3−4i|2+|Z+2−7i|2+|Z−5+2i|2 at a+ib, then a+b+λ is equal to
Find the area (in square units) of the parallelogram whose sides are x + 2y + 3 = 0, 3x + 4y - 5 = 0, 2x + 4y + 5 = 0 and 3x + 4y - 10 = 0.
Number of integers greater than 7000 and divisible by 5 that can be formed using only the digits 3,5,7,8 and 9, no digit being repeated, is
In how many ways can 7 pictures be hung from 5 picture nails on a wall?
Consider the lines given by L1: x + 3y - 5 = 0, L2: 3x - ky - 1 = 0 and L3: 5x + 2y - 12 = 0. If one of L1, L2 and L3 is parallel to at least one of the other two, then
For what values of c does the equation 2x2 + 3x + c = 0 have imaginary roots?
If the rth, (r + 1)th and (r + 2)th coefficients of (1 + x)n are in AP, then n is a root of the equation
The value of eccentricity for the hyperbola x2 - 2y2 - 2x + 8y - 1 = 0 is
A ray of light coming along the line y=√3x+2 after striking the line y= 3, gets reflected, so the path of reflected light will be along the line -
Sum of maximum & minimum values of f(x)=x3+2x2+2x−1 in interval x∈[0,4] is
Coefficients of variation of two distributions are 50 and 60 and their arithmetic mean are 30 and 25 respectively. Difference of their standard deviation is