A conducting sphere of radius 10 cm has unknown charge. If the electric field at a distance 20 cm from the centre of the sphere is 1.2 × 103 N C-1 and points radially inwards. The net charge on the sphere is

Question

A conducting sphere of radius 10 cm has unknown charge. If the electric field at a distance 20 cm from the centre of the sphere is 1.2 × 103 N C-1 and points radially inwards. The net charge on the sphere is (A) -4.5 × 10-9 C (B) 4.5 × 109 C (C) -5.3 × 10-9 C (D) 5.3 × 109 C

Tardigrade Admin · Accepted Answer

Here, distance of point from the centre of the sphere, r = 20 cm = 0.2 m Electric field, E = -1.2 × 103 N C-1 As E=(q/4πε0r2) ∴ q=(4πε0r2)E=((0.2)2×(-1.2×103)/9×109) =-5.3×10-9 C

Q. A conducting sphere of radius $10 c m$ has unknown charge. If the electric field at a distance $20 c m$ from the centre of the sphere is $1.2 \times 1 0^{3} N C^{- 1}$ and points radially inwards. The net charge on the sphere is

$- 4.5 \times 1 0^{- 9} C$

$4.5 \times 1 0^{9} C$

$- 5.3 \times 1 0^{- 9} C$

$5.3 \times 1 0^{9} C$

Q. A conducting sphere of radius 10cm has unknown charge. If the electric field at a distance 20cm from the centre of the sphere is 1.2×103NC−1 and points radially inwards. The net charge on the sphere is

−4.5×10−9C

4.5×109C

−5.3×10−9C

5.3×109C

Here, distance of point from the centre of the sphere, r=20cm=0.2m Electric field, E=−1.2×103NC−1 As E=4πε0​r2q​ ∴q=(4πε0​r2)E=9×109(0.2)2×(−1.2×103)​ =−5.3×10−9C

Q. A conducting sphere of radius $10 c m$ has unknown charge. If the electric field at a distance $20 c m$ from the centre of the sphere is $1.2 \times 1 0^{3} N C^{- 1}$ and points radially inwards. The net charge on the sphere is

$- 4.5 \times 1 0^{- 9} C$

$4.5 \times 1 0^{9} C$

$- 5.3 \times 1 0^{- 9} C$

$5.3 \times 1 0^{9} C$