One
If you use the right hand rule for these problems, you usually make your fingers and thumb sit at right angles to each other. What each of the two fingers means and that related to the thumb is a different story. All you have to understand at this point is that all three are mutually perpendicular.
That makes C the answer.
All the other choices don't make that clear.
Two
This is a straight definition question. The definition says exactly what D says.
Distance to the moon = 4×
m.
1 m = 3.28 ft
Distance to the moon in ft = 4×
×3.28 ft
= 13.12 ×
ft
1 fathom = 6 ft
Hence, distance to the moon in fathom
=
×
≈ 2×
fathom
<span>If the forces are acting in exactly opposite directions, they will subtract, and the magnitude of the resultant force is 6 N. This is the minimum resultant force, so that rules out (1). Similarly, if they act in exactly the same direction, they will add, and the resultant force is 18 N. This will be the maximum resultant force. That rules out (3) and (4). Thus, at some angle (between 0 and 180 degrees), you COULD find a resultant force of 15 N.</span>
1 Ampere
Explanation:
1/R = 1/8 + 1/10 + 1/12
1/R = (30 + 24 + 20) / 240
1/R = 74 / 240
R = 240 / 37
R = 120/37 Ohms
We know that,
V = IR
I = V/R
I = 12 / (120/37)
I = 12 × 37/120
I = 37/10
I = 3.7 A
Now,
The current in 12 ohm resistor →
= 1 A
∴ The current in 12 ohm resistor is 1 ampere