A solid sphere and a hollow sphere are heated the same temperature. Point out the true statement.
hollow sphere cools more quickly
both hollow and solid sphere cools more quickly
solid sphere cools more quickly
none of the statement is true
The time period of a simple pendulum is T remaining at rest inside a lift. Find the time period of pendulum when lift starts to move up with an acceleration of g/4
T
T/2
1 Kcal of heat flowing through a rod iron. When the rod is cut down to 4 pieces then what will be the heat flowing through each piece having same differential temperature?
1/2 Kcal
1/4 Kcal
1 Kcal
1/15 Kcal
C.
1 Kcal
We know that the heat flowing through a conductor is given by
⇒ Q = -KA
Where K = thermal conductivity of the material
A = area of cross-section
= temperature gradient
t = time
Now if we cut the rod into 4 pieces, A remains same K remains same, so for same time t, Q is going to be same as earlier.
If fundamental frequency is 50 and next successive frequencies are 150 and 250 then it is
a pipe closed at both end
a pipe closed at one end
an open pipe
a stretched pipe
If hot water is mixed with cold water
temperature first increases then become constant
temperature first decreases then become constant
increases continuously
first it is uncertain then it become constant
For liquid to rise in a capillary tube, the angle of contact should be
acute
obtuse
right
none of these
The heat produced in a long wire is characterized by resistance, current and time through which the current passes. If the errors in measuring these quantities are respectively 1 %, 2% and 1%, then the total error in calculating the energy produced is
4%
6%
4/3 %
8%
Anatomy and Bismuth are usually used in thermocouple, because
a constant e..m.f is produced
higher thermo e.m.f is produced
a negative e.m.f is produced
lower thermo e.m.f is produced