Answer:
The focal length fe of the eyepiece is <em>2.86 cm</em>
Explanation:
Since we are given the telescope's magnification and the length of the tube, we can use the expressions
<em>M = f_o/fe (1)</em> and
<em>l = f_o + fe (2)</em>
where
- M is the telescope's magnification
- l is the length of the tube
- fe is the focal length of the eye-piece
Rearranging equation (2) to make f_o the subject of the formula, we get
<em>f_o = l - fe</em>
Substituting the above equation into equation (1) we get
<em>M = (l - fe)/fe ⇒ fe = l/(M +1)</em>
<em> ⇒ fe = 60/(20 + 1)</em>
⇒ <em>fe = 2.86 cm</em>
The correct option is PROVIDE ELECTRICAL ENERGY.
The marked cell in the given electric circuit is the battery and the function of the battery in electric cells is to provide electrical energy that will drive the electrical current in the electric circuit. A battery in an electric circuit is thus a source of energy for the circuit.
Answer:
False
Explanation:
It is false because the greater the force, the greater the friction.
A scenario a red ball might appear black is when there is a shadow in front of it.or when the ball is in a dark place.
Answer:
The frequency of the coil is 7.07 Hz
Explanation:
Given;
number of turn of the coil, N = 200 turn
area of the coil, A = 300 cm² = 0.03 m²
magnitude of magnetic field, B = 30 mT = 0.03 T
maximum value of induced emf, E = 8 V
The maximum induced emf in the coil is given by;
E = NBAω
E = NBA(2πf)

where;
f is the frequency of the coil

Therefore, the frequency of the coil is 7.07 Hz