A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that his density remains same, the stress in the leg will change by a factor of :

A conical pendulum of length 1 m makes an angle $$\theta$$ = 45o w.r.t. Z-axis and moves in a circle in the XY plane. The radius of the circle is 0.4 m and its center is vertically below O. The speed of the pendulum, in its circular path, will be: (Take g = 10 ms−2 )

What is the conductivity of a semiconductor sale having electron concentration of $$5\times 10^{18}{m}^{-3},$$ hole concentration of $$5\times 10^{19}{m}^{-3},$$ electron mobility of 2.0 m2 V$$-$$1 s-1 and hole mobility of 0.01 m2 V$$-$$1 s$$-$$1 ? (Take charge of electronas 1.6 $$\times$$ 10 $$-$$19 c)

The V-I characteristic of a diode is shown in the figure. The ratio of forward to reverse bias resistance is :

The current gain of a common emitter amplifier is 69. If the emitter current is 7.0 mA, collector current is :

In a common emitter amplifier circuit using an n-p-n transistor, the phase difference between the input and the output voltages will be:

A block of mass 0.1 kg is connected to an elastic spring of spring constant 640 Nm−1 and oscillates in a damping medium of damping constant 10−2 kg s−1 . The system dissipates its energy gradually. The time taken for its mechanical energy of vibration to drop to half of its initial value, is closest to :

The ratio of maximum acceleration to maximum velocity in a simple harmonic motion is 10 s−1 . At, t = 0 the displacement is 5 m. What is the maximum acceleration ? The initial phase is {\pi \over 4}.

A 1 kg block attached to a spring vibrates with a frequency of 1 Hz on a frictionless horizontal table. Two springs identical to the original spring are attached in parallel to an 8 kg block placed on the same table. So, the frequency of vibration of the 8 kg block is :

A particle is executing simple harmonic motion with a time period T. At time t = 0, it is at its position of equilibrium. The kinetic energy – time graph of the particle will look like:

The electric field component of a monochromatic radiation is given by $$\overrightarrow{E}$$ = 2 E0 $$\hat{i}$$ cos kz cos $$\omega$$t Its magnetic field $$\overrightarrow{B}$$ is then given by :

Magnetic field in a plane electromagnetic wave is given by $$\overrightarrow{B}$$ = B0 sin (k x + $$\omega$$t) $$\hat{j}T$$ Expression for corresponding electric field will be : Where c is speed of light.

An object is dropped from a height h from the ground. Every time it hits the ground it looses 50% of its kinetic energy. The total distance covered as t $$\to$$ $$\infty$$ is :

A body of mass m = 10–2 kg is moving in a medium and experiences a frictional force F = –kv2. Its initial speed is v0 = 10 ms–1. If, after 10 s, its energy is {1 \over 8}mv_0^2, the value of k will be:

A time dependent force F = 6t acts on a particle of mass 1 kg. If the particle starts from rest, the work done by the force during the first 1 sec. will be:

A sinusoidal voltage of peak value 283 V and angular frequency 320/s is applied to a series LCR circuit. Given that R=5 $$\Omega$$, L=25 mH and C=1000 $$\mu$$F. The total impedance, and phase difference between the voltage across the source and the current will respectively be :

A signal is to be transmitted through a wave of wavelength $$\lambda$$, using a linear antenna. The length l of the antenna and effective power radiated Peff will be given respectively as : (K is a constant of proportionality)

A signal of frequency 20 kHz and peak voltage of 5 Volt is used to modulate a carrier wave of frequency 1.2 MHz and peak voltage 25 Volts. Choose the correct statement.

In amplitude modulation, sinusoidal carrier frequency used is denoted by $${\omega }_c$$ and the signal frequency is denoted by $${\omega }_m$$. The bandwidth ($$\Delta {\omega }_m$$) of the signal is such that $$\Delta {\omega }_m$$ < < $${\omega }_c$$. Which of the following frequencies is not contained in the modulated wave?

Two deuterons undergo nuclear fusion to form a Helium nucleus. Energy released in this process is : (given binding energy per nucleon for deuteron = 1.1 MeV and for helium = 7.0 MeV)