Question
‘A’ and ‘B’ can do a piece of work in 30 days
and 40 days, respectively. They started working together but ‘A’ left after 9 days. Find the time taken by ‘B’ to complete the remaining work.Solution
Let total amount of work be 120 units (LCM of 30 and 40). Efficiency of ‘A’ = 120/30 = 4 units/day Efficiency of ‘B’ = 120/40 = 3 units/day Amount of work done by ‘A’ and ‘B’ together in 9 days = (4 + 3) × 9 = 63 units Time taken by B to complete remaining work = {(120 – 63)/3} = 19 days
Compared to fresh Water, the freezing point of sea water is -
A pulse of light duration 10-5 s is absorbed fully by a little object initially at rest. If the power of this pulse is 45 × 10-3...
Newton’s second law of motion primarily explains which of the following?
The colour of sky appears blue due to –
When an electric current flows, electrons move from:
What is the unit of electric current?
Current sensitivity of a moving coil galvanometer is 9 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 30 div/V. The...
What does the slope of a velocity-time graph represent?
An object is projected vertically upward from Earth's surface with speed
v 0 = √(GM/1.5R). The maximum height reached from the center of E...
A rubber ball is dropped from a height of 2 metres. To what height will it rise if there is no loss of energy/velocity after rebounding?
Relevant for Exams:
