The KE and PE of a particle executing SHM of amplitude a will be equal when displacement is
2a
D.
The equation where the symbols carry the usual meaning and A, T and λ are positive, represents a wave of
amplitude 2 A
period T/λ
speed xλ
speed
A pipe open at both the ends produces a note of fundamental frequency f1 . When the pipe is kept with th of its length in water, it produces a note of fundamental frequency f2 . The ratio of is
2
An electric water kettle rated 2.1 kW is filled with 1.5 kg of water at 20°C. How many seconds does it take to reache boiling point of water ? Assume that there are no heat losses from the kettle. Specific heat capacity of water is 4200 Jkg-1 K-1 .
60
120
240
480
An immersion heater with electrical resistance 7 Ω is immersed in 0.1 kg of water at 20°C for 3 min. If the flow of current is 4 A, what is the final temperature of the water in ideal conditions ? (Specific heat capacity of water = 4.2x 103 Jkg-1 K-1)
28°C
48°C
52°C
68°C
Heat produced (cals) in a resistance R when a current I amperes flows through it for t seconds is given by the expression
A red coloured object illuminated by mercury vapour lamp, when seen through a green filter, will appear
red
blue
violet
black
The modulus of elasticity is dimensionally equivalent to
strain
force
stress
coefficient of viscosity
Radius of an air bubble at the bottom of the lake is r and it becomes 2 r when the air bubble rises to the top surface of the lake. If P cm of water be the atmospheric pressure, then the depth ofthe lake is
2 P
8 P
4 P
7 P
A manometer connected to a closed tap reads 4.5 x 105 Pa. When the tap is opened the reading of the manometer falls to 4 x 105 Pa. Then the velocity of flow of water is
7 ms-1
8 ms-1
9 ms-1
10 ms-1