Answer is Option C Lumen.It is also known as luminous energy.
In a parallel circuit, the equivalent resistance is the reciprocal of (the sum of the individual reciprocals).
1/R = 1/10 + 1/21 + 1/13
1/R = 0.225 mhos
R = 4.45 ohms
I = V / R
The total current out of the battery is
I = (9v)/(4.45ohms)
I = 2.02 Amperes
As the total current leaves the battery, it splits into 3 paths, and each resistor gets part of it. The 10ohm resistor gets the most current; the 21ohm resistor gets the least current. After flowing through the resistors, the 3 currents join and add up to 2.02 Amperes again, and the same current returns to the battery.
Each resistor has the same 9v of EMF across it.
Answer: 12.0 m/s^2
Explanation:
Let
be the angular acceleration of the end of the rod
Taking torque about the link, we have:

Torque is also given in terms of moment of inertia of the rod and its angular acceleration i.e.

From equations (i) and (ii) we have:

The acceleration of the end of the rod farthest from the link is given by:

Explanation:
The fluctuating sound heard when two objects vibrate with different frequencies is called beats. It is given that guitar string produces 3 beats/s when sounded with a 352 Hz tuning fork and 8 beats/s when sounded with a 357 Hz tuning fork.
It is assumed to find the vibrational frequency of the string.
For 3 beats/s, beat frequency can be :
352 - 3 or 352 + 3 = 349 Hz or 355 Hz
For 8 beats/s, beat frequency can be :
357 - 8 or 357 + 8 = 349 Hz or 365 Hz
It means that the vibrational frequency is 349 Hz.