If M = Mass, L = Length, T = Time and I = Electric current, then the dimensional formula for electrical resistance R is given by
[R] = [M1L2T-3I-2]
[R] = [M1L2T-3I2]
[R] = [M1L2T3I-2]
[R] = [M1L2T3I2]
A body is moving at a speed near 0.3 ms-1. To measure its speed with an accuracy about 1%, using a sampling distance 3 mm, the measuring clock should have a least count of the order of
0.1 s
0.01 s
0.001 s
0.0001 s
A train moves from one station to another in 2 hours time. Its speed-time graph during this motion is shown below. The maximum acceleration during the journey is
140 kmh-2
160 kmh-2
100 kmh-2
120 kmh-2
A body dropped from a height h with an initial speed zero reaches the ground with a velocity of 3 km/h. Another body of the same mass was dropped from the same height h with an initial speed 4 km/h will reach the ground with a velocity of
3 km/h
4 km/h
5 km/h
12 km/h
If the acceleration due to gravity is 10 ms-2 and the units of length and time are changed to kilometre and hour respectively, the numerical value of the acceleration due to gravity is
360000
72000
36000
129600
A boat man can row with a speed of 10 km/h in still water. If the river flows at 5 km/h, the direction in which the boat man should row to reach a point on the other bank directly opposite to the point from where he started is (width of the river is 2 km)
in a direction inclined at 120° to the direction of river flow
in a direction inclined at 90° to the direction of river flow
60° in the north-west direction
should row directly along the river flow
The maximum and minimum magnitudes of the resultant of two given vectors are 17 units and 7 units respectively. If these two vectors are at right angles to each other, the magnitude of their resultant is
14
16
18
13
A cricketer can throw a ball to a maximum horizontal distance of 100 m. The speed with which he throws the ball is (to the nearest integer)
30 ms-1
42 ms-1
32 ms-1
35 ms-1
A.
30 ms-1
A box whose mass is 5 kg lies on a spring balance inside a lift. The lift starts to ascend with an acceleration of 2 ms-2. The reading of the machine or balance is (g = 10 ms-2)
50 kg
zero
49 kg
60 kg
A ball of mass 0.5 kg moving with a velocity of 2 ms-1 strikes a wall normally and bounces back with the same speed. If the time of contact between the ball and wall is 10-3 s, the average force exerted by the wall on the ball is
1125 N
1000 N
500 N
2000 N