1
JEE Main 2019 (Online) 8th April Evening Slot
+4
-1
Young's moduli of two wires A and B are in the ratio 7 : 4. Wire A is 2 m long and has radius R. Wire B is 1.5 m long and has radius 2 mm. If the two wires stretch by the same length for a given load, then the value of R is close to :-
A
1.7 mm
B
1.9 mm
C
1.3 mm
D
1.5 mm
2
JEE Main 2019 (Online) 8th April Morning Slot
+4
-1
A boy's catapult is made of rubber cord which is 42 cm long, with 6 mm diameter of cross-section and of negligible mass. The boy keeps a stone weighing 0.02kg on it and stretches the cord by 20 cm by applying a constant force. When released, the stone flies off with a velocity of 20 ms–1. Neglect the change in the area of cross-section of the cord while stretched. The Young's modulus of rubber is closest to:
A
104 Nm–2
B
106 Nm–2
C
108 Nm–2
D
103 Nm–2
3
JEE Main 2019 (Online) 8th April Morning Slot
+4
-1
Water from a pipe is coming at a rate of 100 litres per minute. If the radius of the pipe is 5 cm, the Reynolds number for the flow is of the order of : (density of water = 1000 kg/m3, coefficient of viscosity of water = 1mPas)
A
106
B
104
C
103
D
102
4
JEE Main 2019 (Online) 8th April Morning Slot
+4
-1
A steel wire having a radius of 2.0 mm, carrying a load of 4 kg, is hanging from a ceiling. Given that g = 3.1 p ms–2, what will be the tensile stress that would be developed in the wire ?
A
3.1 × 106 Nm–2
B
6.2 × 106 Nm–2
C
4.8 × 106 Nm–2
D
5.2 × 106 Nm–2
EXAM MAP
Medical
NEET