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31.
An aeroplane is moving in a circular path with a speed 250 km/hr. What is the change in velocity in half revolution ?
(1)500 km/hr
(2)250 km/hr
(3)125 km/hr
(4)Zero
32.
The value of (A+B)×(A−B) is
(1)0
(2)A2−B2
(3)B×A
(4)2(B×A)
33.
The diagonals of a parallelogram are 2i and 2j. What is the area of the parallelogram
(1)0.5 units
(2)1 unit
(3)2 units
(4)4 units
34.
The pitch of the screw guage is 1mmand there are 100 divisions on the circular scale. When nothing is put inbetween the jaws, the zero of the circular scale lines 8 divisions below the reference line. When a wire isplaced between the jaws, the first linear scale division is clearly visible while 72nddivision on circular scale coincides with the reference line. The radius of the wire is:
(1)1.64mm
(2)1.80mm
(3)0.82mm
(4)0.90mm
35.
If A and B are perpendicular vectors and vector A=5i+7j−3k and B=2i+2j−ak. The value of a is
(1)– 2
(2)8
(3)– 7
(4)– 8
36.
Electrons in a TV tube move horizontally South to North. Vertical component of earth’s magnetic field points down. The electron is deflected towards
(1)West
(2)No deflection
(3)East
(4)North to South
37.
Given: a+b=c and a+2b=R. If R is perpendicular to a, find |c||b|.
(1)3
(2)2
(3)1
(4)0
38.
A particle moves with a velocity 6i−4j+3km/sunder the influence of a constant forceF=20i+15j−5kN. The instantaneous power applied to the particle is
(1)35 J/s
(2)45 J/s
(3)25 J/s
(4)195 J/s
39.
If for two vector A and B, sum (A+B) is perpendicular to the difference (A−B). The ratio of their magnitude is
(1)1
(2)2
(3)3
(4)None of these
40.
If Z =C4A2B3, then the relative error in Z will be :
(1)A∆A+B∆B+C∆C
(2)A2∆A+B3∆B−C4∆C
(3)A2∆A+B3∆B+C4∆C
(4)A∆A+B∆B−C∆C
41.
If two vectors P=i+2mj+mk and Q=4i−2j+mk are perpendicular to each other. Then, the value of m will be:
(1)1
(2)-l
(3)- 3
(4)2
42.
Angle between the two vectors 2i+5j and i+j+k is cos−1(α). The value of α is
(1)866
(2)877
(3)888
(4)899
43.
The angle between two vectors given by 6i+6j−3k and 7i+4j+4k is
(1)cos−1(31)
(2)cos−1(35)
(3)sin−1(32)
(4)sin−1(35)
44.
Let A=iAcosθ+jAsinθ, be any vector. Another vector B which is normal to A is :-
(1)Bcosθi+Bsinθj
(2)Bsinθi+Bcosθj
(3)Bsinθi−Bcosθj
(4)Acosθi−Acosθj
45.
If a vector 2i+3j+8k is perpendicular to the vector 4j−4i+αk. Then the value of α is
(1)–1
(2)21
(3)−21
(4)1
46.
What is the unit vector perpendicular to the following vectors 2i+2j−k and 6i−3j+2k
(1)517i+10j−18k
(2)517i−10j+18k
(3)517i−10j−18k
(4)517i+10j+18k
47.
A body, constrained to move in the Y-direction is subjected to a force given by F=(−2i+15j+6k)N. What is the work done by this force in moving the body a distance 10 m along the Y-axis
(1)20 J
(2)150 J
(3)160 J
(4)190 J
48.
A vector F1 is along the positive X-axis. If its vector product with another vector F2 is zero then F2 could be
(1)4j
(2)−(i+j)
(3)(j+k)
(4)(−4i)
49.
The dimensional formula of angular impulse is :
(1)ML−2T−1
(2)ML2T−2
(3)MLT−1
(4)ML2T−1
50.
The resultant of the two vectors having magnitude 2 and 3 is 1. What is their cross product
(1)6
(2)3
(3)1
(4)0
51.
A force F=5i+6j+4k acting on a body, produces a displacement S=6i−5k. Work done by the force is
(1)10 units
(2)18 units
(3)11 units
(4)5 units
52.
A sliver wire has mass (0.6±0.006)g, radius (0,5 ± 0.005) mm and length (4 ± 0.04) cm. The maximum percentage error in the measurement of its density will be :
(1)4%
(2)3%
(3)6%
(4)7%
53.
Two adjacent sides of a parallelogram are represented by the two vectors i+2j+3k and 3i−2j+k. What is the area of parallelogram
(1)8
(2)83
(3)38
(4)192
54.
Find out the unit vector perpendicular to both vectors i–j+k and i+j+k.
(1)i+j
(2)2−i+k
(3)j+k
(4)i+j2
55.
A body, acted upon by a force of 50 N is displaced through a distance 10 meter in a direction making an angle of 60° with the force. The work done by the force be
(1)200 J
(2)100 J
(3)300
(4)250 J
56.
If a and b are two-unit vectors such that a+2b and 5a−4b are perpendicular to each other, then the angle between a and b is
(1)45∘
(2)60∘
(3)cos−1(31)
(4)cos−1(72)
57.
If ϵ0 is the permittivity of free space and E is the electric field, then ϵ0E2 has the dimensions :
(1)M−1L−3T4A2
(2)ML2T−2
(3)M0L−2TA
(4)ML−1T−2
58.
The area of a square is 5.29cm2. The area of 7 such squares taking into account the significant figures is:
(1)37cm2
(2)37.030cm2
(3)37.03cm2
(4)37.0cm2
59.
The equation of state of a real gas is given by (P+V2a)(V−b)=RT, where P,V and T are pressure. volume and temperature respectively and R is the universal gas constant. The dimensions of b2a is similar to that of :
(1)PV
(2)P
(3)RT
(4)R
60.
If a vector (2i+3j+8k) is perpendicular to the vector −4i+4j+αk, then the value of α is-