✓ 1 MARKS
MCQ
🔥 APPEARED IN 3 BOARD SETS
A plane electromagnetic wave travels through a medium and the magnetic field associated with it is given by $B = 5 \times 10^{-8} \sin (3 \times 10^{10} t - 150 x) \text{ T}$ where x is in metres and t is in seconds. The velocity of the wave is :
A
$2.0 \times 10^8 \text{ m s}^{-1}$
B
$4.5 \times 10^7 \text{ m s}^{-1}$
C
$3.5 \times 10^7 \text{ m s}^{-1}$
D
$2.5 \times 10^8 \text{ m s}^{-1}$
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2026 | Series 55-3 | Set 1 | Question 3 |
| CBSE 2026 | Series 55-3 | Set 2 | Question 10 |
| CBSE 2026 | Series 55-3 | Set 3 | Question 1 |
02 // OFFICIAL CBSE MARKING SCHEME BREAKDOWN
- Step 1: Stating the fundamental formula / law statement (+1 Mark)
- Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
- Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)