Question
A potentiometer wire of length 1 m has a resistance of 5
Ω. It is connected to a 6 V battery in series with a resistance of 10 Ω. Determine the emf of the primary cell which gives a balance point at 80 cm.Solution
Length (l) = 1 m Resistance of potentiometer wire = 10Ω Current (I) in potentiometer wire = V/(R + R') = 6/(10 + 5) = 6/15 = 0.4 A Potential gradient (k) = IRp/L = (0.4 × 10)/1 = 4 Vm-1 e = kl = 4 × 0.8 = 3.2 V
A is cycling at an average speed of 24 km/hr such that he can reach a certain point at 12 noon. If he cycles at 36 km/hr, then he will reach the destina...
A cheetah spotted a fox running away at 6 m/s and started chasing it at 10 m/s. The fox was 120 metres ahead at that moment. Find the time taken by the ...
Driving at (4/5) of his usual speed, a man reaches his destination 36 minutes late. Find the time he normally takes to cover the distance.
If the diameter of a sphere is 42 cm, find the total surface area of the sphere.
Two trains for Mumbai leave Delhi at 6 a.m. and 6:30 a.m. and travel at 100 km/h and 136 km/h respectively. Approx. how many km from Delhi will the two ...
‘A’ and ‘B’ started moving towards each other at same time with a speed of 12 km/hr and 16 km/hr, respectively. If the distance covered by ‘B ...
- Two bikers, ‘C’ and ‘D’, start from point ‘R’ and ‘S’ respectively towards each other. They meet after 7 hours, and biker ‘D’ has trave...
‘A’ and ‘B’ started moving towards each other at same time with a speed of 22 km/hr and 33 km/hr, respectively. If the distance covered by ‘A�...
- Bus 'X' and Bus 'Y' start together from a station heading in the same direction. Bus 'X' moves at 18 km/h while Bus 'Y' moves at 30 km/h. Determine the dis...
The ratio of the speeds of Y and Z is 7 : 5. When Y increases his speed by 40%, he covers 294 km in 3 hours. Find the time taken by Z to cover 200 km.
Relevant for Exams:
