The radii and Young's moduli of two uniform wires A and B are in the ratio 2 : 1 and 1 : 2 respectively. Both wires are subjected to the same longitudinal force. If the increase in length of the wire A is one percent the percentage increase in length of the wire B is
A. 1.0
B. 1.5
C. 2.0
D. 3.0
The pair of physical quantities not having the same dimensional formula is :
A. acceleration, gravitational field strength
B. torque, angular momentum
C. pressure, modulus of elasticity
D. all of the above
The extension of a wire by application of a load is 0.3 cm.The extension in a wire of same material, but of double the length and half the radius of cross-section, by the same load will be, in cm :
A. 0.3
B. 0.6
C. 1.2
D. 2.4
The fundamental physical quantities that have same dimensions in the dimensional formula of torque and angular momentum are
A. mass, time
B. time, length
C. mass, length
D. time, mole
The dark lines in the solar spectrum are due to:
A. Absorption of certain wavelengths by elements present in the outer layer
B. Absence of certain elements in the sun
C. Black body radiation from the sun
D. Scattering of light
In CGS system the magnitude of the force is 100 dynes. In another system where the fundamental physical quantities are kilogram, meter and minute, the magnitude of the force is:
A. 0.036
B. 0.36
C. 3.6
D. 36
The velocity v (in cm/sec) of a particle is given in terms of time t (in sec) by the equation,V = at + [b / (t+c)]. The dimensions of a,b,c are
A. L2,T,LT2
B. LT2,LT,L
C. LT-2,L,T
D. L,LT,T2