Question
The speed of a boat in still water is 30 km/hr. If the
boat covers 160 km in upstream in 8 hours, then find the time taken by the boat to travel 160 km in downstream.Solution
Let the speed of the boat in still water and the speed of the current be ‘x’ km/hr and ‘y’ km/hr, respectively Upstream speed of the boat = (x – y) = 160/8 = 20 km/hr Or, 30 – y = 20 Or, y = 30 – 20 = 10 km/hr Therefore, downstream speed of the boat = 30 + 10 = 40 km/hr Required time taken = 160/40 = 4 hours
In a charged conductor, where do the electrical charges tend to reside?
Which of the following quantities is a scalar? Â
The refractive index of glass is 1.5. What is the speed of light in glass?
(Speed of light in vacuum is 3.0 ×108 m s-1)
Two capacitors of 6 µF and 3 µF are connected in series and a potential difference of 90 V is applied. The energy stored in the system is:
Find the resistance when a current of 2 A flows under a voltage of 10 V. Â
What is the current flowing through a 24 Ω resistor connected to a 12 V battery?
Who laid the foundations of Quantum Theory?
A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves:
A plane mirror is placed on a wall. A man walks directly toward the mirror at 2 m/s. The speed at which his image approaches him is:
Compared to fresh Water, the freezing point of sea water is -
Relevant for Exams:
