The current in a circuit is defined as I=dqdt. The charge (q) flowing through a circuit, as a function of time (t), is given by q=5t2-20t+3. The minimum charge flows through the circuit at:
t=4 sec
t=2 sec
t= 6 sec
t=3 sec
The current in a circuit is defined as I=dqdt. If the charge (q) flowing through a circuit is given by q=(t2-3t+4), current flowing through the circuit is equal to zero at:
t=1.5 sec
t=15 sec
Work done by a force (F) in displacing a body by dx is given by W=∫F(x).dx. If the force is given as a function of displacement (x) by F(x)=(x2-2x+1)N, then work done by the force from x=0 to x=3 m is:
3 J
6 J
9 J
21 J
The impulse due to a force on a body is given by I=∫Fdt. If the force applied on a body is given as a function of time (t) as F=(3t2+2t+5)N, then impulse on the body between t=3 sec to t = 5 sec is:
216 kg-m/sec
124 kg-m/sec
175 kg-m/sec
41 kg-m/sec
Which of the following option is not true, if →A = 3ˆi + 4ˆj and →B = 6ˆi + 8ˆj, where A and B are the magnitudes of →A and →B?
→A × →B = →0
AB = 12
→A·→B = 48
A = 5
The angle made by the vector →A = √3ˆi + 3ˆj + 2ˆk with y-axis is:
sin-1(3√14)
sin-1(√74)
cos-1(43)
cos-1(35)
In the space, if the sum of vectors of unequal magnitude is zero, then the minimum number of vectors are
2
3
4
5
If →A + →B is perpendicular to →A - →B , then which of the following statement is correct?
|→A| = |→B|
→A ⊥ →B
→A·→B = zero
(→A + →B)·(→A - →B) ≠ 0
The angle between the two vectors (-2ˆi + 3ˆj + ˆk) and (ˆi + 2ˆj - 4ˆk) is:
0°
90°
180°
45°
If →a + →b + →c = →0; then which of the following statements is incorrect?
→a, →b and →c must each be a null vector.
The magnitude of →a+→b equals the magnitude of →c.
The magnitude of ä can never be greater than the sum of the magnitudes of →b and →c
ä must lie in the plane of →b and →c.
When a force of magnitude F acts on a body of mass m the acceleration produced in the body is a. If three coplanar forces of equal magnitude F act on the same body as shown in the figure, then acceleration produced is
1. 0
2. (√3 + 1)a
3. (√3 - 1)a
4. √3a>
Three forces each of magnitude 1 N act along with the sides AB, BC, and CD of a regular hexagon. The magnitude of their resultant is:
4N
Zero
2 N
1 N
If a unit vector ˆj is rotated through an angle of 45° anticlockwise, then the new vector will be:
√2ˆi + √2ˆj
ˆi + ˆj
1√2ˆi + 1√2ˆj
-1√2ˆi + 1√2ˆj
If →a = 2ˆi + ˆj and →b = 3ˆi + 2ˆj, then |→a × →b|=?
1
√65
8
→A and →B are two vectors given by →A = 2ˆi + 3ˆj and →B = ˆi + ˆj. The component of → Aparallel to →B is:
12(2ˆi - ˆj)
52(ˆi - ˆj)
52(ˆi + ˆj)
(3ˆi - 2ˆj)2
If a vector is inclined at angles, α, β, and γ with x, y, and z-axis respectively, then the value of sin2 α + sin2 β+ sin2 γ is equal to
0
12
If ˆp is the unit vector in the direction →B, then:
ˆp = |→B|→B
ˆp = |→B| × →B
ˆp = →B|→B|
ˆp = →B→B
Which of the following sets of forces cannot give zero resultant?
3 N, 4 N, 5 N
9 N, 8 N, 7 N
16 N, 2 N, 17 N
30 N, 5 N, 24 N
The minimum number of non-coplanar vectors whose vector sum can be zero is:
The resultant vector of →P and →Q makes angle θ1 with →P and θ2 with →Q.Then-
θ1 > θ2
θ1 < θ2 if P > Q
θ1 < θ2 if P < Q
θ1 > θ2 if P = Q
A vector →A, which has magnitude 8.0 is added to a vector →B which lies on the x-axis. The sum of these two vectors lies on the y-axis and has a magnitude twice the magnitude of →B. The magnitude of the vector →B
8√5
√2 × 8
If →A = 2ˆi + 3ˆj + 6ˆk and →B = 3ˆi + 2ˆj - ˆk, then the unit vector in the direction of →A + →B is
(ˆi - ˆj - ˆk)√3
(ˆi + ˆj - ˆk)√3
(ˆi + ˆj + ˆk)√3
(ˆi - ˆj + ˆk)√3
The forces F1 and F2 are acting perpendicular to each other at a point and have resultant R. If force F2 is replaced by R2 - F21F2 acting in the direction opposite to that of F2, the magnitude of resultant
Becomes half
Becomes double
Becomes one third
Remains the same
A force of 20 N acts on a particle along a direction, making an angle of 60° with the vertical. The component of the force along the vertical direction will be
5 N
10 N
20 N
If →A and →B are two vectors inclined to each other at an angle θ, then the component of →A perpendicular to →B and lying in the plane containing →A and →B will be:
→A→.BB2→B
→A - →A→.BB2→B
→A - →B
→A + →B
If |→A| ≠ |→B| and |→A × →B| = |→A · →B|, then
→A ∥ →B
→A is antiparallel to →B
→A is inclined to →B at an angle of 45°
If →R is the resultant of two vectors →A and →B and →R' is the difference in them, and |→R| = |→R'|, then:
→A makes an angle of 120° with →B
Two forces of the same magnitude are acting on a body in the East and North directions, respectively. If the body remains in equilibrium, then the third force should be applied in the direction of:
North-East
North-West
South-West
South-East
Given are two vectors, →A= (2ˆi - 5ˆj + 2ˆk) and →B = (4ˆi - 10ˆj + cˆk). What should be the value of c so that vector →A and →B would become parallel to each other?
In the following questions, a statement of assertion (A) is followed by a statement of the reason (R).
A: A vector must have, magnitude and direction.
R: A physical quantity cannot be called a vector if its magnitude is zero.
If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
If Assertion is a true statement but Reason is false, then mark (3).
If both Assertion and Reason are false statements, then mark (4).
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