A resistance R of thermal coefficient of resistivity = α is connected in parallel with a resistance = 3R, having thermal coefficient of resistivity = 2α. Find the value of αeff.
Two cars A and B are approaching each other as shown in figure.
At t = 0, the velocities of A and B are v1 and v2 and they are at x = 0 and x = x0, respectively. The car A is moving with constant velocity while B is moving with constant acceleration a, whose direction is shown. If Xrel, Vrel and arel are displacement, velocity and acceleration of A w.r.t. B respectively, then mark out the correct options.
Suppose the potential energy between electron and proton at a distance r is given by . Application of Bohr's theory to hydrogen atom in this case shows that
For the circuit shown in the figure, find the current (in ampere) through the source.
Suppose the potential energy between an electron and a proton at a distance r is given by Ke2 / 3r3. Application of Bohr's theory to hydrogen atom in this case shows that energy in the nth orbit is proportional to nx then x=
A disc of radius R rotating with an angular velocity ω0 is placed on a rough horizontal surface. If initial velocity of centre of disc is zero, then velocity of centre of disc when it ceases to slip, comes out to be ω0R/k, value of k is _____.
A 20 cm long string, having a mass of 1.0 g, is fixed at both the ends. The tension in the string is 0.5 N. The string is set into vibrations using an external vibrator of frequency 100 Hz. Find the separation (in cm) between the successive nodes on the string.
A block is moving on an inclined plane making an angle 45° with the horizontal and the coefficient of friction is μ. The force required to just push it up the inclined plane is 3 times the force required to just prevent it from sliding down. If we define N = 10 μ, then N is
Steel wire of length L' at 40°C is suspended from the ceiling and then a mass 'm' is hung from its free end. The wire is cooled down from 40°C to 30°C to regain its original length 'L'. The coefficient of linear thermal expansion of the steel is 10-5/°C, Young's modulus of steel is 1011 N/m2 and radius of the wire is 1 mm. Assume that L >> diameter of the wire. Then the value of 'm' in kg is
(Round off up to 2 decimal places)
Consider the partition to be rigidly fixed so that it does not move. When equilibrium is achieved, the final temperature of the gases will be ____ K.
Now consider the partition to be free to move without friction so that the pressure of gases in both compartments is the same. Then, magnitude of total work done by the gases till the time they achieve equilibrium will be kR. Find the value of k.
The magnitude of the induced electric field in the orbit at any instant of time during the time interval of the magnetic field change is BR/t. Find the value of t.
The change in the magnetic dipole moment associated with the orbit, at the end of time interval of the magnetic field change, is . Find the value of p.
A man is standing on top of a building 100 m high. He throws two balls vertically, one at t = 0 and after a time interval (less than 22 seconds). The later ball is thrown at a velocity of half the first. At t = 2 s, both the balls reach their maximum heights. At this time the vertical gap between first and second ball is +15m.
The speed of the first ball is
A man is standing on top of a building 100 m high. He throws two balls vertically, one at t = 0 and after a time interval (less than 22 seconds). The later ball is thrown at a velocity of half the first. At t = 2 s, both the balls reach their maximum heights. At this time the vertical gap between first and second ball is +15m.
The time interval between the throw of balls is
Which of the following statements is/are true for P4S3 molecule -
The equilibrium constant Kp for this reaction at 298 K is . Find the value of k.
For the given reaction, KC < n. Find the value of n.
The total number of N-atoms present in compound R is
The sum of N- and O-atoms present in compound T is
The orthocentre of the triangle F1MN is . Find the value of k.
If the tangents to the ellipse at M and N meet at R and the normal to the parabola at M meets the x-axis at Q, then the ratio of area of the triangle MQR to area of the quadrilateral MF1NF2 is m : n. Find the sum of m and n.
The probability that x1 + x2 + x3 is odd is
The probability that x1, x2 and x3 are in an arithmetic progression is
The ends Q and R of two thin wires, PQ and RS, are soldered (joined) together. Initially each of the wires has a length of 1 m at 10°C. Now, the end P is maintained at 10°C, while the end S is heated and maintained at 400°C. The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ is twice that of the wire RS and the coefficient of linear thermal expansion of PQ is 1.2 x 10–5 K–1, the change in length of the wire PQ is
The switch in circuit shifts from 1 to 2 when VC > 2V/3 and goes back to 1 from 2 when VC < V/3. The voltmetre reads voltage as plotted. What is the period T of the wave form in terms of R and C?
Consider the cell:
Cd(s) | Cd2+ (1.0 M) || Cu2+ (1.0, M) | Cu(s)
If we want to make a cell with a more positive voltage using the same substances, we should
The van der Waals' constants for three different gases are given in the table below:
Which of the following interpretations is incorrect?
If f(x) = x tan-1x, find the value of f'(1)
If the tangent at any point on the curve y = f(x) intercepted between the point and the x-axis is of length 1, find the equation of the curve.
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