A point performs simple harmonic oscillation of period T and the equation of motion is given x = a sin (ωt + π/6). After the elapse of what fraction of the time period the velocity of the point will be equal to half of its maximum velocity?
T/8
T/6
T/3
T/3
The wave described by y = 0.25 sin (10 π x -2 πt), where x and y are in metre and t in second, is a wave travelling along the
- ve x direction with frequency 1 Hz
+ve x direction with frequency π Hz and wavelength λ = 0.2 m
+ve x direction with frequency 1 Hz and wavelength λ = 0.2 m
+ve x direction with frequency 1 Hz and wavelength λ = 0.2 m
At 10o C the value of the density of a fixed mass of an ideal gas divided by its pressure is x. At 110o C this ratio is
x
383x/283
10x/110
10x/110
The electric potential at a point in free space due to a charge Q coulomb is Q x 1011 V. The electric field at that point is
The voltage gain of an amplifier with 9% negative feedback is 10. The voltage gain without feedback will be
90
10
1.25
1.25
The energy required to charge a parallel plate condenser of plate separation d and plate area of cross-section A such that the uniform electric field between the plates is E, is
A current of 3 A flows through the 2 Ω resistor shown in the circuit. The power dissiated in the 5 Ω resistor is
diagram
4 W
2 W
1 W
1 W
D.
1 W
Voltage across 2 Ω is same as voltage across arm containing 1 Ω and 5 Ω resistance.
Voltage across 2 Ω resistance,
V = 2 x 3 = 6 V
So, voltage across lowest arm,
V1 = 6 V
Current across 5 Ω, I = 6/ 1+6 = 1 A
Thus, power across 5 Ω,
P = I2R = (1)2 x 5 = 5 W
A particle mass m, charge Q and kinetic energy T enter a transverse uniform magnetic field of induction. After 3 s the kinetic energy of the particle will be
3T
2T
T
T
A wire of a certain material is stretched slowly by ten percent. Its new resistance and specific resistance become respectively
1.2 times, 1.1 times
1.21 times, same
both remain the same
both remain the same
In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of
excitation of electrons in the atoms
a collision between the atoms of the gas
a collision between the charged particle emitted from the cathode and the atoms of the gas
a collision between the charged particle emitted from the cathode and the atoms of the gas