A body is said
to have a uniform velocity, which of the following relation will hold for
average and instantaneous velocities?
a) average velocity is greater than the instantaneous velocities
b) instantaneous velocity is zero
c) Average velocity is zero
d) average velocity is equal to the
instantaneous velocity
If percentage is uncertain in force (F ) and area ( A) are 2% and 5 % respectively then what will be the percentage uncertainty in pressure (P) exerted by the force on the area ?
a) 2%
b) 5%
c) 7%
d) 3%
Explanation: To determine the percentage uncertainty in pressure (P) exerted by the force on the area, we can use the formula:
Percentage uncertainty in P = Percentage uncertainty in F + Percentage uncertainty in A
Given: Percentage uncertainty in F = 2% Percentage uncertainty in A = 5%
Plugging in these values into the formula, we get:
Percentage uncertainty in P = 2% + 5% Percentage uncertainty in P = 7%
Therefore, the correct answer is: c) 7%
If fo is 10m and fe is 0.1m so what will be magnification of refracting telescope?
a) 100m
b) 100
c) 10
d)10m
Explanation: As magnification of refracting telescope is M=fo/fe so putting values.
Thus we have M = (10 m)/(0.1 m) = 100
A cable break
if stretched by more than 2mm. it is cut into two equal parts. how much either
part can be stretched without breaking?
a) 25m
b) 10mm
c) 0.522
d) 1mm
Explanation: If a cable breaks when stretched by more than 2mm and is then cut into two equal parts, the maximum stretch that either part can undergo without breaking can be determined.
Since each part is now half the length of the original cable, the maximum stretch that each part can undergo without breaking is also halved.
Therefore, the maximum stretch that either part can be stretched without breaking is:
2mm / 2 = 1mm
Therefore, the correct answer is: d) 1mm
