Q21.If P × Q = Q × P , the angle between P and Q is θ(0°< θ < 360°). The value of θ will be ___ ° .
What This Question Tests
This question tests the fundamental property of vector cross product (anti-commutativity) and the condition for a zero cross product.
Concepts Tested
Formulas Used
P x Q = |P||Q|sinθ n̂
Q x P = - P x Q
📚 NCERT Sections This Tests
2.1 — Two Charges 5 × 10–8 C And –3 × 10–8 C Are Located 16 Cm Apart. At
Physics Class 11 · Chapter 2
2.1 Two charges 5 × 10–8 C and –3 × 10–8 C are located 16 cm apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.
4.5 — What Is The Magnitude Of Magnetic Force Per Unit Length On A Wire
Physics Class 11 · Chapter 4
4.5 What is the magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30º with the direction of a uniform magnetic field of 0.15 T?
1.14 — Consider A Uniform Electric Field E = 3 × 103 Î N/C. (A) What Is The
Physics Class 11 · Chapter 1
1.14 Consider a uniform electric field E = 3 × 103 î N/C. (a) What is the flux of this field through a square of 10 cm on a side whose plane is parallel to the yz plane? (b) What is the flux through the same square if the normal to its plane makes a 60° angle with the x-axis?
📋 Question Details
- Chapter
- Vectors & 3D
- Topic
- Vector Cross Product
- Year
- 2021
- Shift
- 25 Feb Shift 2
- Q Number
- Q21
- Type
- Numerical
- NCERT Ref
- Class 11 Physics Ch 4: Motion in a Plane
More from this Chapter
Q1. In the cube of side 'a' shown in the figure, the vector from the central point of the face ABOD to the central point of the face BEFO will be: (1) 1 a (2) 1 2 (ˆk −ˆi) 2 a(ˆi −ˆk) (3) 1 (4) 1 2 a(ˆj −ˆi) 2 a(ˆj −ˆk)
Q21.Three particles P, Q and R are moving along the vectors A = ˆi +ˆj, B = ˆj + ˆk and C = −ˆi +ˆj, respectively. They strike on a point and start to move in different directions. Now particle P is moving normal to the plane → → → which contains vector A and B. Similarly particle Q is moving normal to the plane which contains vector A → and C. The angle between the direction of motion of P and Q is cos−1( √x1 ). Then the value of x is .
Q21.If the projection of 2 ^𝑖+ 4 ^𝑗- 2 ^𝑘 on ^𝑖+ 2 ^𝑗+ 𝛼 ^𝑘 is zero. Then, the value of 𝛼 will be
Q21.For three vectors →A = (−x^i −6^j −2^k), →B = (−^i + 4^j + 3^k) and →C = (−8^i −^j + 3^k), if →A ⋅(→B × →C) = 0, then value of x is _________