A water film is made between two 10 cm long straight wires and at a distance of 0.5 cm. If distance between the wires is increased by 1 mm, then work done will be (T = 7.2 x 10-2N/m)
7.22 × 10-6 J
1.44 × 10-5 J
2.88 × 10-5 J
5.76 × 10-5 J
The average kinetic energy of a hydrogen gas molecule at NTP will be (Boltzmann's constant k = 138 x 10-23 J/K)
0.186 × 10-20 J
0.372 × 10-20 J
0.56 × 10-20 J
5.6 × 10-20 J
The height of a water fall is 84 m. Assuming that the entire kinetic energy of falling water is converted into heat, the rise in temperature of the water will be
0.196°C
1.960°C
0.96°C
0.0196°C
If a body loses half of its velocity on penetrating 3 cm in a wooden block then how much will it penetrate more before coming to rest?
1 cm
2 cm
3 cm
4 cm
The minimum velocity (in ms-1) with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction to avoid skidding is
60
30
15
25
A steel ball is dropped from a height h and it makes a perfectly elastic collision with a horizontal plane. Following its initial release, it will make periodic motion with frequency
If the earth is treated as a sphere of radius R and mass M, its angular momentum about the axis of rotation with time period T is
A child swinging on a swing in sitting position, stands up, then the time period of swing will
increase
decrease
remain same
increase if the child is long and decrease if the child is short
B.
decrease
As the girl stands up, the effective length of pendulum decreases due to the reason that the centre of gravity rises up so, according to
T will decrease.
A mass of 10 g moving horizontally with a velocity of 100 cm/s strikes a pendulum bob of mass 10 g. The two masses stick together. The maximum height reached by the system now is (g = 10 m/s2)
zero
5 cm
2.5 cm
1.25 cm
A particle of mass 10 g is executing simple harmonic motion with an amplitude of 0.5 m and periodic time of (/ 5) second. The maximum value of the force acting on the particle is
25 N
5 N
2.5 N
0.5 N