**Reactance of Rotor at Given Slip**

To determine the reactance of the rotor at a given slip, we need to consider the slip formula and the relationship between slip and rotor frequency.

**Slip Formula:**
The slip of an induction motor is defined as the difference between the synchronous speed and the actual rotor speed, divided by the synchronous speed. It is represented by the symbol 's' and is given by the formula:

s = (Ns - Nr) / Ns

Where:
- s: Slip
- Ns: Synchronous speed
- Nr: Rotor speed

**Synchronous Speed:**
The synchronous speed of an induction motor is given by the formula:

Ns = (120 * f) / P

Where:
- Ns: Synchronous speed (in RPM)
- f: Frequency of the supply (in Hz)
- P: Number of poles

**Given Parameters:**
- Slip (s) = 0.01
- Supply frequency (f) = 50 Hz

**Calculating Synchronous Speed:**
Let's calculate the synchronous speed of the induction motor using the given frequency and assuming a 4-pole motor:

Ns = (120 * 50) / 4
Ns = 1500 RPM

**Calculating Rotor Speed:**
The rotor speed can be calculated using the slip formula:

s = (Ns - Nr) / Ns

0.01 = (1500 - Nr) / 1500

Solving for Nr:

0.01 * 1500 = 1500 - Nr
15 = 1500 - Nr
Nr = 1500 - 15
Nr = 1485 RPM

**Calculating Reactance of Rotor:**
The reactance of the rotor can be calculated using the formula:

Xr = 2 * π * f * Lr * s

Where:
- Xr: Reactance of rotor
- π: Pi (approximately 3.14159)
- f: Frequency of the supply (in Hz)
- Lr: Rotor inductance (in Henry)
- s: Slip

Given:
- Rotor inductance (Lr) = 1 Henry
- Slip (s) = 0.01
- Supply frequency (f) = 50 Hz

Substituting the values:

Xr = 2 * 3.14159 * 50 * 1 * 0.01
Xr = 3.14159 ohms

Therefore, the reactance of the rotor at a slip of 0.01 is approximately 3.14159 ohms.