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=∫Fx.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→ = 3i^ + 4j^ and B→ = 6i^ + 8j^, 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→ = 3i^ + 3j^ + 2k^ with y-axis is:
sin-1314
sin-174
cos-143
cos-135
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 -2i^ + 3j^ + k^ and i^ + 2j^ - 4k^ 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 + 1a
3. 3 - 1a
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 j^ is rotated through an angle of 45° anticlockwise, then the new vector will be:
2i^ + 2j^
i^ + j^
12i^ + 12j^
-12i^ + 12j^
If a→ = 2i^ + j^ and b→ = 3i^ + 2j^, then a→ × b→=?
1
65
8
A→ and B→ are two vectors given by A →= 2i^ + 3j^ and B→ = i^ + j^. The component of A→ parallel to B→ is:
122i^ - j^
52i^ - j^
52i^ + j^
3i^ - 2j^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 p^ is the unit vector in the direction B→, then:
p^ = B→B→
p^ = 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→
85
2 × 8
If A→ = 2i^ + 3j^ + 6k^ and B→ = 3i^ + 2j^ - k^, then the unit vector in the direction of A→ + B→ is
i^ - j^ - k^3
i^ + j^ - k^3
i^ + j^ + k^3
i^ - j^ + k^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 - F12F2 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→.B→B2B→
A→ - A→.B→B2B→
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→= (2i^ - 5j^ + 2k^) and B→ = (4i^ - 10j^ + ck^). 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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